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Eight Sleep Bed Cooling System Review

Published:
Last Updated: Dec 18, 2023

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This article contains affiliate links, which means that I may receive a commission if you make a purchase using these links.

The Eight Sleep Pod system uses water-based cooling technology to help your body achieve and maintain an ideal temperature during sleep. This can increase both the duration and quality of your sleep, making it more likely that you’ll wake up feeling fully rested and refreshed. 

Additionally, the system features advanced, built-in sleep tracking technology (called the Active Grid) that can measure your heart rate, heart rate variability, and a range of other sleep-related biometrics.

My wife and I have been using Eight Sleep since August 2020, and in this review, I’ll explain how it works, why temperature is important for optimal sleep, and how it has changed our sleep for the better.

Eight Sleep Pod 3 Review: The Best Bed Cooling Solution on the Market?

First, it’s important to note that Eight Sleep can be used with any mattress, including your current mattress. While the company sells its own line of memory foam mattresses, the heartbeat of the system is the Pod Cover, which is what contains the temperature control and sleep tracking technology.

The Pod Cover is available as a standalone item and is substantially less expensive than the complete system. So if you’re happy with your current mattress, there’s no reason to switch.

The Role of Temperature In Sleep Quality

Two important factors that directly influence sleep quality are the temperature in your bedroom and your body’s ability to regulate its own temperature.

There are several reasons for this:

  • Your body temperature naturally declines throughout the night based on your circadian rhythm.
  • Falling asleep requires your core temperature to decline by about two degrees.
  • Feeling too hot, and the subsequent need to remove covers, disrupts your sleep.

Every cell in your body follows what’s known as a circadian rhythm. Think of it as a biological clock that influences the release of certain hormones, such as cortisol in the morning and melatonin in the evening. 

As part of that circadian rhythm, your body starts to slowly cool down as you approach bedtime, and its temperature continues to decline until a few hours before waking up. 

As a result, sleep environments that interfere with this natural cooling process — for example, because the thermostat is set too high or because you have a bed that retains too much body heat — can negatively impact sleep quality.

One of the easiest ways to support the body’s natural cooling-off period before sleep onset is to keep your bedroom temperature set between 60 and 67 degrees Fahrenheit. Of course, if you have a central HVAC system (like we do), this burns a lot of energy, and it can take a while to cool the house down to your desired temperature. 

Plus, your partner might have different temperature perception than you, which could make it difficult to find a temperature you both feel comfortable with.

A bed-cooling solution like Eight Sleep addresses all of these issues by enabling you and your partner to set specific temperatures for the individual stages of your sleep.

Why We Chose Eight Sleep

Eight Sleep System

Michael Kummer

The Eight Sleep System
Comfort
Temperature control
Sleep tracking
Value

Summary

Eight Sleep is the best bed cooling solution available, thanks to its advanced technology and many customization options. We’ve used it for more than two years and it has notably improved our sleep quality. Plus, you can buy the Pod Cover as a stand-alone item and use it with your current mattress.

4.6

Humans sleep best in a dark and cool environment. Our bodies are genetically conditioned to sleep in darkness, on a cold surface (usually the padded floor of a cave), and covered by (heavy) animal skins and fur. 

While my wife and I were able to figure out how to make our room dark and cold, we struggled to control the temperature under the covers. As a result, we would often overheat in the middle of the night.

I would sometimes exacerbate that situation by having a high-fat dinner (at the end of a 24-hour fast); the energy my body would expend digesting a high-calorie meal increased my body temperature, further preventing me from falling asleep or getting into the restorative stages of sleep.

As a result, I was looking for solutions that would help me better regulate my body temperature. 

At first, I was looking into so-called “bed fans” that blow air under the sheets, but I wasn’t convinced they were the most practical solution. Plus, constant air flow can cause moisture loss in your skin, which isn’t ideal for skin health.

In the summer of 2020, I stumbled across an ad for Eight Sleep on Instagram and got excited about the technology. So I reached out to the company and they graciously agreed to send me their original Pod Pro for testing. 

We have since upgraded from the Pod Pro to the Pod 3, and the following sections reflect the latest features and technology of the Eight Sleep platform.

I also want to point out that when I first published this review, most Eight Sleep features — including advanced sleep and biometrics tracking, automatic software updates and smart alarms — were available to all users.

Unfortunately, Eight Sleep decided to make those features available only to customers who sign up for an annual subscription. As a result, I restructured this article to better reflect which features are free and which ones now require a paid membership.

My Eight Sleep Review After 1,000+ Nights

Eight Sleep - We've had the Eight Sleep system since summer of 2020.
We’ve had the Eight Sleep system since the summer of 2020. Here’s what it looks like in our bedroom.

Based on my research and testing, Eight Sleep offers the most advanced “cooling mattress” and sleep technology on the market. We’ve used Eight Sleep for nearly three years, and have noticed a dramatic improvement in our sleep quality as measured by how much time we spend in the restorative phases of sleep (deep and REM sleep), how quickly we fall asleep (sleep onset), how often we wake up during the night, and how refreshed we wake up each morning. 

This review covers the complete Eight sleep system, which consists of the following: 

  1. The Pod 3 Cover, which contains the “Active Grid” technology that provides temperature control and sleep tracking. This cover can be used on any mattress (even the one you currently own). 
  2. The Hub, which is the central engine that powers the Pod 3 Cover. This is where you add the water that gets circulated throughout the Active Grid (for the purpose of temperature control). 
  3. The Pod Mattress, which is a relatively standard memory foam mattress designed with temperature regulation in mind. 

We sleep on the full Eight Sleep system, but you only need the Cover and the Hub. The Pod Mattress is completely optional. We chose to go with the complete Pod system because our old mattress was already 10 years old and ready for replacement.

Pros

  • Allows you to set a precise sleep temperature as low as 55 degrees Fahrenheit (and as high as 110 degrees Fahrenheit).
  • Has dual-zone support, so you and your partner can set different sleep temperatures.
  • Features a smart alarm that uses a combination of gentle vibration and temperature change to wake you up.
  • Integrates with Apple Health, Oura, Peloton and more.
  • Offers data-driven sleep and health coaching (via Span Health).
  • The Hub’s water tank lasts for several months before you need to refill it.

Cons

  • The sleep tracking data is not always 100% accurate, though it has gotten much better with the Pod 3 (as compared to the previous generation Pod cover).
  • Adds more electronics to your bedroom, which increases your exposure to EMFs and blue light (you can turn off the status LED).
  • Requires WiFi (even at night), which also increases your exposure to EMFs and prevents you from turning off your WiFi router.
  • Many of the more advanced features (that used to be free) are part of a paid subscription.

Unboxing and Setup

Setting up the Eight Sleep system is relatively straightforward and only takes a few minutes.

Eight Sleep Pod Pro: Unboxing + How to Install

Something worth pointing out is that if you purchase both the Pod 3 Cover and the optional memory foam mattress, the two items might ship in separate packages and likely won’t arrive on the same day. We received a box with the memory foam mattress first, while the Pod 3 Cover and Hub arrived a few days later.

Don’t be discouraged if the mattress looks thinner than you had anticipated. The plastic wrapping compresses the memory foam, and it takes a few minutes for the mattress to expand after the plastic has come off. Unlike many memory foam mattresses that need to be aired out for hours or even days, our Eight Sleep mattress did not smell at all.

The next step includes zipping on the Pod 3 Cover and routing the cable along the headboard of your bed to where you intend to position the Hub. 

Once that’s complete, plug in the water connections (which carry water from the Hub to the Cover), the USB cable (which connects the Pod 3 Cover to the Hub), and the power cord. Just make sure that the Hub isn’t too close to any furniture, because it needs to be able to circulate air via the built-in fan. 

Last but not least, you can use the Eight Sleep mobile app (available for iOS and Android) to hook up the Hub to your WiFi network and “prime” the system. (“Priming” means flushing out the air from the water tubes and filling them with water.)

The app will guide you through all of these steps, but make sure you use filtered or distilled water, and make sure you add two tablespoons of hydrogen peroxide every time you fill the water tank; this will help prevent mold and other microorganisms from growing inside the tubes. 

Pod 3 Mattress (Optional)

Eight Sleep - Foam Mattress Layers copy
The layers of the Eight Sleep mattress.

Both my wife and I prefer softer mattresses, because we’ve found that harder mattresses cause pressure points. That became an issue the last time we visited my family in Austria and stayed with my mom and her husband — the bed we slept on had a super-firm mattress that made us feel like we were sleeping on an unpadded floor. 

On the other hand, I don’t like a mattress that doesn’t provide enough support to keep my spine and other body parts properly aligned.

Eight Sleep claims that their mattress is made with either five or six layers of CertiPUR-US-certified foam (depending on the model you purchase) and has an ideal “medium” firmness for providing contouring support. 

The CertiPUR-US certification ensures that the foam was manufactured without the use of ozone-depleting chlorofluorocarbons, heavy metals, formaldehyde and phthalates, and that it has low VOC emissions. In other words, the mattress was produced in an environmentally-friendly manner and off-gassing is greatly reduced.

After having slept on our Eight Sleep mattress for a few years, my wife and I have concluded that our mattress is neither too firm nor too soft. It’s comfortable and provides the proper amount of support based on our preferences. 

In fact, it’s the best mattress I’ve ever slept on, and I appreciate that it’s more breathable than some of the all-foam mattresses I’ve tried in the past.

What confuses some people is that Eight Sleep doesn’t sell the mattress as a stand-alone item; it’s only available in combination with the Pod Cover and the Hub. In other words, while you can buy the Pod Cover separately and use it with your current mattress, you cannot buy the Eight Sleep mattress without also getting the Pod Cover.

Temperature Control

Getting started with creating your own temperature profile.
Getting started with creating your own temperature profile.

While Eight Sleep’s mattress is comfortable and better at temperature regulation than many competing memory foam options, the company’s innovative temperature control technology is the system’s main selling point and its most valuable feature. 

How it works is that the Pod Cover (not the mattress itself) features a grid of soft water tubes (made from silicone) that are sewn into the fabric. The Hub (which is the system’s power source and has a water tank) connects to the Pod Cover and circulates water through those tubes at the desired temperature.

In other words, the Hub heats or cools the water to the desired temperature (based on what stage of sleep you’re in and environmental factors, such as the ambient room temperature) before circulating it through the tubes. 

One common question is whether you can feel the silicone tubes of the Pod Cover when you’re in bed. The good news is that the tubes are so soft that you don’t feel them. Of course, if you run your fingers over the fitted sheet, you can tell there’s something soft underneath, but the rest of your body won’t be able to tell the difference between a mattress with or without the Pod Cover.

It’s worth noting that you can control the temperature of either side of the mattress individually. So if your partner likes to sleep warmer or colder, that’s an option.

As far as the temperature range is concerned, you can set the Pod Cover to anywhere between “minus 10” to “plus 10” using the Eight Sleep app. That +/-10 scale represents an actual temperature range of 55 to 110 Fahrenheit (13 to 43 Celsius). 

For the first night, I set the temperature to a relatively low setting (-8) and it felt like I was sleeping on a frozen lake.

Your natural body temperature…
Your natural body temperature over the course of a day.

Since then, I’ve been experimenting with different temperature settings to find the one that works best for me. I’ve also been using Eight Sleep’s Autopilot feature (part of the Eight Sleep paid subscription plan) that can automatically adjust the temperature settings based on my sleep history and changes in the environment (e.g., room temperature).

Autopilot is very helpful because your body temperature naturally changes over the course of the night. Plus, your temperature perception can vary based on factors like humidity and the ambient temperature in your room (or even outside).

Eight Sleep takes the ambient temperature into account.
Eight Sleep takes the ambient temperature into account.

That’s why Eight Sleep includes sensors in the Active Grid that measure the ambient temperature. These sensors enable the Pod Cover to learn from your environment and make smarter temperature recommendations. 

Additionally, you have the option to define different temperature settings for the various stages of sleep, including:

  • Bedtime
  • Initial sleep stage (deep sleep)
  • Final sleep stage (REM sleep)
  • Wake up

As part of the setup process — after installing the app and pairing it with the Hub — you can define whether you’re a hot, super hot, cold, or super cold sleeper. The app will then recommend the initial temperature settings. 

Of course, you can also simply rely on Autopilot.

In practice, the Pod Cover starts cooling down your mattress (or heating it up, depending on your preference) about an hour before your predefined bedtime. 

As you fall asleep (i.e., during the initial sleep stage), the Pod Cover adjusts the temperature to support slow-wave sleep (also known as deep sleep), an important stage of sleep that occurs in longer periods during the first half of the night.

What’s interesting is that your core temperature is typically the lowest a few hours before you wake up, and at a time when most of your REM sleep occurs. Studies have shown that during this phase of sleep, your body’s thermoregulation capabilities are impaired

In other words, your body could be susceptible to losing too much heat, which can cause you to wake up. You may have experienced this phenomenon, where you wake up during the second half of the night and feel freezing because you uncovered yourself during the first half of the night.

That’s why I have my Pod Cover set to slightly increase the temperature under the covers for my final sleep stage, before cranking up the heat at the very end to encourage me to get out of bed. 

Overall, I think the incredibly wide temperature range offered by the Pod Cover should be able to accommodate most sleepers. For those extra “hot” sleepers, Eight Sleep offers a specialized mattress called the Pod 3 Max, which includes a heat-dissipating fabric the company calls MaxChill.

In other words, if you tend to sweat a lot while sleeping and suspect that a mattress surface temperature of 55 degrees Fahrenheit might not be cold enough (the lowest the Pod Cover can go), you might want to consider getting the full Eight Sleep system with the Pod 3 Max mattress, as the MaxChill fabric improves airflow and thus reduces the chance for hot air getting trapped around your body.

Eight Sleep Pro and Plus Membership (Cost and Features)

As I mentioned in the introduction, many of the most useful features Eight Sleep offers via its mobile app are now part of the company’s paid membership program. When you purchase an Eight Sleep system, the first 12 months of the membership are mandatory, but you can cancel your subscription after a year. 

While many new customers appear to be OK with paying an annual fee for features such as sleep tracking and vibration alarms, I am shocked that Eight Sleep has started charging for features that used to be free. 

Fortunately, I was grandfathered in and can continue using the full suite of features without having to pay. But adding an annual cost of at least $180 on top of the system’s purchase price might turn some customers off.

Eight Sleep currently offers two membership options, as shown in the comparison table below.

ProPlus
Price$180 per year$288 per year
Automatic temperature adjustments (Autopilot)☑️☑️
Vibration and thermal alarm☑️☑️
Automatic software updates☑️☑️
Sleep and health reports☑️☑️
Extended warrantyNo☑️
The only difference is the extended warranty.

Before Eight Sleep restructured its membership model, the Autopilot feature was part of the now-discontinued (but optional) subscription program called 8+ Pro. All other features listed here were available free of charge.

Let’s dive into the system’s features so you can decide if they’re worth paying for.

Automatic Temperature Adjustments (Autopilot)

If you subscribe to either the Pro or Plus membership, you get access to Eight Sleep’s Autopilot feature, which can automatically adjust the temperature of each side of the system based on a number of factors. 

These factors include:

  • Age
  • Sleep debt
  • Personal sleep history with the system
  • Past temperature preferences
  • Historical and real-time bedroom temperature
  • Historical and real-time local weather
  • User feedback and input over time

Every morning, you can see the changes that were automatically made while you were sleeping. You then have the ability to give manual feedback about your sleep in order to better train the system’s algorithm.

For example, every so often the Eight Sleep app asks how the temperature settings felt the night before (i.e., if you were too hot or too cold during the various stages of sleep). Based on your answers — along with the other factors the system takes into consideration — Autopilot will continually learn how to adjust your bed temperature to further improve your sleep.

In my view, Autopilot can be useful if some of the factors listed above change frequently. We have a fairly consistent bedtime and we keep our bedroom at a consistent temperature, so we turned autopilot off and just rely on the predefined temperature settings that have proven to work well for us.

Sleep Tracking

Eight Sleep - More Deep Sleep with Lower Temperatures
Choosing the “extremely cold” setting led to more deep sleep than usual.

Sleep tracking is one of my passions, so I was excited to find out how the non-wearable technology of Eight Sleep would compare to my WHOOP strap and Oura Ring (which are both wearable devices).

Out of the box, Eight Sleep can track the following metrics:

  • Heart rate variability (HRV)
  • Out-of-bed events
  • Respiratory rate
  • Sleeping heart rate
  • Stages of sleep (awake, light, deep, REM)
  • Time to fall asleep
  • Time to leave bed
  • Time spent in bed
  • Toss and turns
  • Wake up consistency

From a technological perspective, Eight Sleep relies on pressure sensors in the Pod Cover to detect body movement (or lack thereof), to count how often your heart beats (heart rate), and to measure the variability between the timing of your heartbeats (HRV). 

As you can imagine, the movement pattern of a beating heart is different from that of your chest as it moves up and down while you breathe. The Pod Cover’s pressure sensors can pick up on those differences to figure out how often you breathe per minute (i.e., your respiratory rate), how often your heart beats, and whether you’re tossing and turning. 

Specifically, your movement patterns and your heart rate can help Eight Sleep figure out both whether you’re actually sleeping and, if so, what stage of sleep you’re in.

However, as I note in my article about the best sleep tracking devices, a lack of movement and a low heart rate aren’t necessarily reliable indicators of sleep. 

While comparing WHOOP with Biostrap (another wrist-worn sleep tracker), I found that Biostrap occasionally thought that I was sleeping while I was actually watching TV on the couch. That’s because I didn’t move for an extended period and my heart rate was very low.

The advantage that Eight Sleep has over other wearables is that it won’t start sleep tracking until you’re actually in bed. Eight Sleep’s assumption is that you go to bed to sleep (or to have sex), but not to watch TV or read a book for extended periods.

That assumption might not match your lifestyle. If so, the Pod Cover might not always accurately detect if you’re sleeping or trying to fall asleep. We’ll talk about those assumptions in more detail later in the article.

As far as sleep tracking is concerned, you should know that Eight Sleep does a fairly good job of figuring out how much time I spend in deep and REM sleep when compared to the data provided by my WHOOP Strap, with both platforms confirming that I spend approximately 40% of my sleep in those restorative phases.

HRV and Respiratory Rate Tracking

Eight Sleep - HRV and HR
A drop in HRV can be a warning sign of an infection.

In addition to the quality of my sleep, I pay very close attention to changes in my HRV and respiratory rate. 

As I mentioned in my WHOOP review, the difference in timing between heartbeats is an indirect indication of how well the nervous system is functioning. If you’re healthy and recovered, there should be a lot of competition between the sympathetic and parasympathetic branches of your nervous system, leading to a high HRV.

If you’re getting sick, or if your body is struggling to recover from stress or strain, your HRV is naturally low — a sign that the sympathetic branch of your nervous system is in overdrive. 

The problem with HRV is that it’s highly volatile. That’s why it only makes sense to measure HRV during sleep (to minimize any influencing factors).

Keeping tabs on your HRV trends can help you determine how recovered your body is, and whether or not you might be getting sick. That’s why I look at my HRV data first thing in the morning to get an assessment of how my body is doing. Most of the time it matches how I feel, although that’s not always the case.

When comparing the HRV data from Eight Sleep and WHOOP, I noticed significant discrepancies as far as the absolute numbers are concerned. 

The reason for those discrepancies is that Eight Sleep measures HRV during different times of sleep than WHOOP does. For example, WHOOP measures HRV during the last five minutes of deep sleep, while Eight Sleep averages your HRV based on several readings taken throughout the night. 

The good news with HRV is that absolute numbers aren’t nearly as significant as relative changes compared to your baseline (trends). Both Eight Sleep and WHOOP have shown similar trend lines, which means that I can rely on either one to assess how my body is doing.

The second factor that can be incredibly helpful in forecasting illness is respiratory rate. That’s because your rate of breathing while asleep is relatively consistent. If that rate suddenly increases, it’s usually a sign of a respiratory problem like sleep apnea or even a viral infection. 

Based on Eight Sleep’s data, my respiratory rate is about 11 breaths per minute and usually ranges from 11.1 to 12.0. WHOOP shows slightly higher numbers (14 to 15 BPM) but the trendlines generated by both platforms look very similar.

Note: I wrote a full article on how to improve your HRV.

Smart Alarm (GentleRise)

Customization options for Eight Sleep's smart alarm.
Customization options for Eight Sleep’s smart alarm.

GentleRise is Eight Sleep’s proprietary smart alarm. It uses a combination of gentle vibrations and a gradual change of temperature to wake you up in the morning. 

Practically, that means you can set an alarm using the Eight Sleep app and the chest area of the mattress will start vibrating at the prescribed time. Additionally, the mattress will gradually heat up or cool down (based on your preferences) as the wakeup time approaches. Of course, you can enable and use both features individually. 

In the event you get out of bed earlier than you had planned, you can dismiss the alarm from your phone before it goes off. That’s particularly helpful if you set the vibration alarm to a level that would disturb your partner.

While GentleRise works very well, there is room for improvement. 

The alarm goes off even if you’re not in bed anymore, or if you forgot to turn it off before leaving town. I think the alarm should only activate when it detects that someone is actually in bed.

Another way that Eight Sleep could improve its smart alarm is by taking sleep data into account. For example, if I have my alarm set to 5:30 a.m., but happen to be in the middle of REM sleep at that time, being woken up could leave me feeling groggy for a few hours. 

I have a fairly consistent bedtime. As a result, I’m usually in light sleep around the time I want to get up. But sometimes, I might go to bed or fall asleep later than usual. That could cause a shift in my sleep cycle that I would like Eight Sleep’s smart alarm to take into account by waking me up a few minutes sooner or later (while I’m in light sleep).

Also, for those rare occasions when I’ve racked up some sleep debt (perhaps because I traveled internationally and struggled with jet lag for a few days), I would love it if there was an option that would wake me up after I slept for a certain amount of time (i.e., 8 hours), instead of at a set time. I know that a consistent wake time is important for my circadian rhythm, but I don’t think it justifies carrying sleep debt.

Overall, I maintain relatively consistent sleep and wake times, but I use the smart alarm as a backstop in the event I don’t wake up at my usual time.

Eight Sleep Mobile App

The Eight Sleep mobile app is feature-rich yet intuitive to use. From the initial setup process to checking out my previous night’s sleep performance in the morning, all the settings and data are easy to find and manipulate.

The home screen shows a prominent on/off button that allows you to quickly control the mattress’ cooling/heating system. Right below, you can fine-tune the temperature settings for the various stages of sleep. Additionally, you can change your desired bed and wakeup times, and customize the smart alarm settings.

However, as with the features listed in the previous section, many of the features discussed below now required a paid subscription.

Sleep Fitness Score

Eight Sleep calculates your personal sleep fitness score every morning.
Eight Sleep calculates your personal sleep fitness score every morning.

The second screen of the Eight Sleep app is reserved for detailed sleep analysis, including your daily sleep fitness score (out of 100). 

To calculate your sleep fitness score, Eight Sleep takes the following factors into account:

  • Time slept
  • Wake up time consistency
  • Time to fall asleep
  • Time to get out of bed

Each factor has a different weight. For example, “time to get out of bed” is significantly less important for determining the quality of your sleep than the first three factors.

Sleep Consistency

Right below the sleep fitness score, you can find a relatively detailed sleep analysis (if you have a Pro or Plus membership) that includes the following metrics:

  1. Time slept
  2. Wake up consistency
  3. Time to fall asleep
  4. Time to get up
  5. Sleep timeline
  6. Sleep stage analysis
  7. Toss and turns
  8. Sleeping heart rate

The first four metrics are meant to help you get insight into your sleep consistency (and how to improve it) by providing a visual indication of whether it falls within an ideal range. 

For example, to best support your circadian rhythm, you should go to bed and wake up within the same 30-minute window every day. If any of the tracked metrics fall outside of the ideal range, you get a penalty on your sleep fitness score.

I really like that idea, but I also recognize that this rating system might not work perfectly for everyone.

My wife likes to read before closing her eyes at night, and also spends a few minutes catching up on emails and social media in the morning. So her total time in bed is much longer than the time she’s asleep. 

Eight Sleep sometimes interprets her lack of movement while reading as an indication that she’s trying to fall asleep. When that happens, she gets a penalty because the app thinks it took her more than 30 minutes to fall asleep. And the next morning she gets another penalty for not getting out of bed quickly enough. 

I appreciate how that can be frustrating, but I also understand where Eight Sleep is coming from. 

For example, the idea of leaving bed right after waking up is to expose yourself to (sun)light. That sends a message to your brain and your circadian rhythm that it’s time to crank up the engine. 

At the same time, I don’t think there’s anything wrong with spending half an hour reading a book (as far as sleep performance is concerned) before calling it a night.

The good news is that you can always manually edit your sleep data and adjust all the captured data to avoid seeing a lower sleep score.

Sleep Stage Analysis

Eight Sleep can track the stages of sleep.
Eight Sleep can track the stages of sleep.

In addition to tracking your sleep consistency, Eight Sleep also offers a detailed sleep stage analysis (as part of its Pro and Plus memberships) that shows you how much time you’ve spent in each of the four sleep stages (awake, light, deep and REM). 

One of the most important aspects of sleep quality is the time you spend in the restorative phases of sleep (deep and REM sleep). What I like about the Eight Sleep app is that it shows you the time you spent in the various stages as percentages. So you can see at a glance if you spent about 40% of your total sleep in those restorative phases.

If I was the person at Eight Sleep responsible for the user interface design, I’d probably add the ability to toggle between percentages and absolute numbers (maybe by tapping the screen), as well as some sort of timeline scrubbing feature. That would make it easier to see exactly what time I entered deep sleep or got up to pee (for example).

Vital Signs

A combination of injury and intense workouts have caused my resting heart rate to rise and my HRV to drop lately.
A combination of injury and intense workouts have caused my resting heart rate to rise and my HRV to drop lately.

The third screen shows a number of important biometrics, including nocturnal HRV, sleeping heart rate and sleeping respiratory rate. These three metrics, and their relative changes over time compared to your baseline, are vital to understanding how your nervous and respiratory systems are doing. 

The app shows you not only the HRV recording from the previous night, but also gives you an indication of what your typical range is (and whether or not last night’s reading is out of range).

I’d like to see the same range information for the sleeping heart rate and respiratory rate, as major discrepancies within these metrics from their respective baselines can indicate a respiratory or other infection, including the common cold or the flu.

Sleep Tools

Eight Sleep System's Sleep Tools
Accessing Sleep Tools requires a subscription.

The last section of the app consists of sleep tools that are part of the paid Pro and Plus membership. It includes a library of audio-visuals and guides that can help you meditate, listen to white noise and sounds from nature, perform deep breathing exercises and more.

It’s also where you’ll find Autopilot.

Integrations

Eight Sleep’s mobile app integrates with multiple third-party platforms to provide “tangible insights into your health and recovery.” 

The current integrations include the following:

  • Apple Health
  • Fitbit
  • Garmin
  • Google Fit
  • Oura
  • Peloton
  • Polar Flow
  • Training Peaks
  • Zwift

Leveraging these integrations means that Eight Sleep can correlate activity — such as rides on your Peloton bike, Oura scores, or runs tracked via Garmin — with changes in your sleep quality. 

As a result, the Eight Sleep app can tell you if your HRV goes up on days that you run or ride your bike. That information enables you to make decisions during the day that will benefit your sleep and recovery. 

In a way, it’s similar to one of my favorite features of the WHOOP Strap, the WHOOP Journal.

Update: On March 30, 2022, Eight Sleep announced the acquisition of Span Health, a platform I’ve used in the past that provides data-driven health and sleep coaching. 

Using Span Health enables you to work directly with a medical doctor and nutritionist to experiment with supplements and lifestyle choices and see how they impact your sleep and recovery.

I’m super excited to see how Eight Sleep will incorporate Span Health to provide even better and more actionable insights into how lifestyle choices impact sleep quality. Eight Sleep’s new coaching services aren’t yet available, but you can join a waitlist and get notified when they officially launch.

Behavior Tags

Eight Sleep Tags and integrations
Tags enable Eight Sleep to correlate behaviors with changes in sleep quality.

Similar to the integrations above, Eight Sleep also has “behavior” tags that allow the app to correlate certain behaviors and lifestyle choices with changes in sleep quality. 

While the number of available tags is somewhat limited, it’s still valuable to see how certain behaviors (like alcohol consumption) impact the quality of your sleep and recovery.

What’s cool is that Eight Sleep can automatically apply certain tags based on activities imported from the connected sources. For example, if you track a HIIT workout using your Apple Watch, Eight Sleep will automatically apply the HIIT tag.

Eight Sleep Labs

Eight Sleep labs
I prefer abstract temperature settings instead of the actual numbers.

Eight Sleep has an invitation-only feature called Eight Sleep Labs that allows some users to test experimental features, such as displaying real temperatures instead of the abstract -10 to +10 settings. 

Eight Sleep Pricing and Options

The complete Eight Sleep system consists of a memory foam mattress, the Pod Cover (which features the Active Grid technology), and the Hub (the central control unit).

Eight Sleep offers the complete system in several different configurations and sizes. The prices in the table below reflect list prices and do not include any sales or discounts.

Additionally, you can purchase the Pod Cover (which includes the Hub) by itself, without the Eight Sleep Mattress.

SystemFullQueenKingCali King
Pod 2 Cover$1,795$1,795$2,095$2,095
Pod 3 Cover$2,095$2,195$2,395$2,395
Pod 3 Cover with PerfectFit$2,195$2,295$2,495$2,495
Pod 3 Mattress$3,095$3,395$3,795$3,795
Pod Pro 3 Max$3,695$3,995$4,395$4,395
The Pod 2 cover is the previous generation model, formerly called the Pod Pro.

As a reminder, purchasing the Pod Cover allows you to use the Eight Sleep cooling technology with any 10-inch to 11-inch mattress, and the Pod 3 Max mattress is meant for extra hot sleepers. For an additional $100, you can get an enhanced version of the Pod 3 Cover that fits any 10-inch to 16-inch mattress; Eight Sleep calls this “PerfectFit.” 

As you can see, the complete Eight Sleep system costs more than some regular mattresses but less than other high-end options from companies such as Sleep Number and Tempur-Pedic — neither of which have the same water-based cooling technology that Eight Sleep offers.

Note that when you purchase an Eight Sleep system, you are required to sign up for either the Pro or Plus membership, which costs $15 or $24 per month respectively. This membership unlocks features such as Autopilot, sleep tracking, software updates, sleep tools and digital coaching and data insights. You can cancel the membership after your first year.

Check Eight Sleep Prices

If you’d like to give Eight Sleep a try, make sure to use the link above and enter coupon code KUMMER at checkout to save $300 off the purchase price of the complete system and $150 off the price of a Pod Cover.

You have 100 nights to try the system and send it back if you don’t like it. Eight Sleep will pay for the return shipping and provide a full refund.

What I Don’t Like About Eight Sleep

I firmly believe that Eight Sleep offers the best mattress or bed cooling solution on the market. Not only does Eight Sleep offer top-notch cooling performance, but its sleep tracking and Autopilot features are spot on.

The only thing I don’t like about Eight Sleep is that the Hub has to be connected to WiFi all night to function. To reduce our exposure to electromagnetic fields (EMFs), we decided to turn off our WiFi infrastructure (consisting of five commercial access points) overnight. 

Unfortunately, we realized that the Hub would stop cooling when our WiFi network shut down for the night. When I asked Eight Sleep about it, the company told me that the Hub constantly sends data to the cloud to adjust the temperature settings throughout the night.

I don’t like that at all! The Hub is capable enough to process my sleep data on-device and without having to send anything to the cloud in real time. Even if that wasn’t possible, I’d be more than happy to forfeit automatic temperature changes in exchange for airplane mode.

I hope Eight Sleep will reconsider and implement airplane mode in a future software update.

Learn more about how EMFs can impact your health.

How Eight Sleep Has Changed Our Sleep

Eight Sleep has dramatically improved the quality of our sleep
Eight Sleep has dramatically improved the quality of our sleep.

In a nutshell, we no longer get too hot or too cold while sleeping. That has reduced the number of disturbances caused by covering or uncovering ourselves during the night. Both my wife and I sleep better, and I have more nights where I spend at least 40% of my sleep in restorative phases.

It’s not that we slept poorly before switching to Eight Sleep; we’ve always kept a relatively strict sleep routine that has produced positive sleep results. But Eight Sleep has helped us to get to the next level of sleep quality.

If you’re someone who has been struggling with getting enough quality sleep, or if you suffer from insomnia or high temperatures in your bedroom, I strongly believe that Eight Sleep can make a huge impact for you.

Pod 3 vs. Pod 2 (And Pod Pro)

Eight Sleep still sells the previous-generation Pod 2 Cover, and if you’re on a budget, you might be wondering if the Pod 3 Cover is worth the extra money. Similarly, if you own the Pod 2 Cover or Pod Pro, you might wonder if you should upgrade to the latest model.

To help answer those questions, here’s an overview of what’s new in the Pod 3 Cover:

  • Double the amount of pressure sensors for improved sleep and biometric tracking accuracy.
  • Improved sensor technology with 4,000 times higher resolution to support advanced sleep and health tracking.
  • 2.4 GHz and 5 GHz WiFi support for better Wi-Fi stability.
  • Upgraded quad-core CPU to crunch the additional data the sensors provide.

To summarize, the Pod 3 Cover features improved sensor technology that facilitates advanced biometric tracking. Plus, support for 5 GHz WiFi can lead to better connectivity if the Hub is placed in an area that’s crowded with devices that are on the 2.4 GHz spectrum. 

Considering that the price difference between the king size Pod 2 System and the Pod 3 System is about $500, I’d stick with the Pod 2 and use the extra cash to invest in the Eight Sleep Carbon Air pillow and a good set of cotton sheets, unless you have flaky WiFi at home and improved sleep tracking are important to you.

I should also mention that, as of this writing, Eight Sleep offers up to $500 for upgrading from an older version of the system to the new Pod 3 System. 

How Does Eight Sleep Compare to Similar Sleep Products?

Eight Sleep vs. Chilisleep [Comparison of Top Bed Cooling Systems]

I also had a chance to try the Cube Sleep System for a couple of weeks and incorporated my feedback into a detailed comparison of the best bed cooling systems and this in-depth Cube Sleep System review

In February 2023, I purchased the Dock Pro from Sleepme (formerly known as Chilisleep) so that I could do a side-by-side comparison. After a few months of testing, I concluded that Dock Pro’s bed cooling capability is on par with Eight Sleep, although the technology supporting the product is nowhere near as sophisticated as Eight Sleep’s. 

Unfortunately, Sleepme appears to be in financial trouble, since all their products have been out of stock for months, their affiliate platform went offline, and all of my contacts at the company were laid off. As a result, I can’t recommend any of Sleepme’s products and I won’t be finishing the Dock Pro review I was writing.

With regard to BedJet and similar products, it’s important to remember that products that blow air under your sheets might make you feel a bit cooler, but they don’t actually change the temperature of the mattress surface. Plus, they can dry out your skin, which isn’t good for maintaining optimal skin health. Eight Sleep can reduce the temperature of the mattress surface to 55 degrees Fahrenheit and keep it there, without making any disturbing noise or airflow.

Frequently Asked Questions

Is Eight Sleep a smart mattress? 

Eight Sleep offers a technology-driven bed cooling system comprised of three elements: a memory foam mattress, a mattress cover (called the Pod Cover) that zips onto the mattress, and a central unit (the Hub) that circulates water through tubes in the mattress cover for the purpose of temperature control.

The mattress itself is not a “smart mattress.” While it is designed with temperature regulation in mind, the system’s smart technology is actually in the mattress cover and the Hub, which you can purchase separately and use on your existing mattress.  

Is Eight Sleep worth it?

Investing in a bed cooling solution has been a game-changer for us, dramatically improving our sleep quality. After using the Eight Sleep system, I can’t imagine sleeping without an actively-cooled mattress cover. While I’m not a fan of the company’s new membership model, I still think the Pod 3 Cover is worth every penny, and I keep recommending it to friends and family.

Does the Eight Sleep system emit electromagnetic fields or radiation (EMF/EMR)?

Neither the Eight Sleep mattress nor the Pod Cover emit EMFs, but the Hub (the device that sits next to the bed) does emit EMFs. However, it’s an extremely low amount that is less than emitted by a box fan that plugs into a wall. I positioned our Hub several feet away from the bed, so I’m not concerned about radiation. You can learn more about my take on EMFs and how I reduce my exposure in this article.

The biggest issue I have with Eight Sleep is that it requires WiFi to be turned on at all times. That’s unfortunate, because wireless access points are a significant source of EMFs that I’d rather avoid while sleeping.

Can you try the Eight Sleep system before placing an order?

Unfortunately, Eight Sleep doesn’t have any brick-and-mortar stores, so it’s not possible to lay down on their products prior to purchasing them. However, Eight Sleep offers a 100-night trial period. If you don’t like it, you can send it back. (And the company will pay for return shipping.)

Do you have to use distilled water with Eight Sleep?

Yes, I highly recommend using distilled or reverse osmosis (RO) filtered water in Eight Sleep to avoid contaminating the pump and silicone tubing with slime-forming bacteria (e.g., manganese or iron bacteria) and dissolved minerals (e.g., calcium and magnesium), both of which can shorten the lifespan of the system.

We’ve been using RO-filtered water in our Eight Sleep system so we don’t have to purchase distilled water in the store. The good news is that you only have to refill Eight Sleep’s water tank every four to six months, so if you keep a couple of gallons of distilled water at home, they’ll last you for a very long time.

Do you have to add hydrogen peroxide to the Eight Sleep water?

Yes, hydrogen peroxide acts as a natural (non-toxic) disinfectant to prevent the growth of bacteria, mold and mildew inside the tubes of the Pod Cover. Considering that Eight Sleep’s tubing and pump are exposed to moisture 24/7, these parts of the system are an ideal breeding ground for pathogens. Hydrogen peroxide mitigates that risk and keeps the entire system sanitary.

That’s particularly important if you don’t use your Eight Sleep system every night (e.g., if you have Eight Sleep in a guest room or vacation home), as standing water is even more likely to grow mold and/or bacteria than flowing water.

Can you set the temperature of each side of the bed individually?

Yes, you can have different temperature settings for each side of the bed.

Is there a noticeable motion transfer between each side of the bed?

Even though Eight Sleep’s high-density foam mattress absorbs some body movement, we’ve experienced noticeable motion transfer when one of us rolls over at night. However, I should mention that I’m not the most considerate bed partner when it comes to moving around. My wife often jokes about how I get airborne when I change from one side of my body to the other. So your mileage may vary.

Can you control the bed with your smart home system?

You can integrate Eight Sleep into your smart home via a service called If This Then That (IFTTT). Through IFTTT, you can use Eight Sleep with Amazon Alexa, Philips Hue lights and a few other devices. Unfortunately, Eight Sleep does not integrate with Apple’s HomeKit, so you can’t use it with Siri.

Is the Pod Mattress good for back sleepers, side sleepers and stomach sleepers?

Yes, the five layers of the Eight Sleep Pod Mattress instantly respond to body impressions and provide pressure relief, regardless of your sleep patterns or sleep position. I usually sleep on my back, but my wife sometimes sleeps on her side or stomach. Neither of us has had any issues as far as support or comfort are concerned. 

Does the Eight Sleep mattress have good edge support?

The Eight Sleep mattress offers decent edge support, but it’s not the best-in-class in that category. I weigh about 210 pounds, and when I get close to the mattress’ edge, I can feel it giving way — but not to an extent that would bother me.

What warranty does Eight Sleep provide?

The mattress is covered by a 10-year warranty. The Pod Cover has a two-year limited warranty. For more information, check out Eight Sleep’s warranty page. If you sign up for the Plus membership, Eight Sleep covers the entire Pod for five years as long as you purchased it through eightsleep.com and have an active subscription.

What is the difference between the Pod 2 Cover and the Pod 3 Cover?

The Pod 3 Cover has twice the number of sensors as the previous-generation mattress topper. Plus, the sensors in the Pod 3 Cover have 4,000 times the resolution, thus enabling the Pod 3 to deliver better sleep and biometrics tracking.

Is Eight Sleep loud?

The Eight Sleep system is incredibly quiet. In fact, the only time we hear the system is when it starts cooling. Even then, we can only hear it when the room is nearly silent and we’re actively listening. In other words, unless you know what to listen for, you probably won’t hear it and won’t be bothered by the noise.

Have you tested any of the Eight Sleep accessories, such as the Carbon Air Pillow, the Air Light Comforter or the Gravity Blanket?

Yes, I also have the Carbon Air Pillow from Eight Sleep and love it. You can check out my review here.

What is the Eight Sleep Pod Pro?

The Eight Sleep Pod Pro used to be the company’s flagship product, before the introduction of the Pod 3. While Eight Sleep doesn’t sell the original Pod Pro anymore, you can still purchase the Pod Pro Cover (which is now called Pod 2 Cover) for less than what the newer Pod 3 Cover costs.

Is the Eight Sleep Hub available in different colors?

No, the Eight Sleep Hub is only available in black.

Does Eight Sleep have a vacation mode?

Yes, Eight Sleep has a vacation mode you can schedule to prevent the system from turning on if you’re away from home for extended periods.

Eight Sleep Review: Final Verdict

Why we chose Eight Sleep

It’s been three years since we got the Eight Sleep system and I have yet to experience a bad night’s sleep. Both my wife and I love the temperature regulation feature of the device, as well as how comfortable the medium-firm mattress feels. 

Compared to our old mattress, which we bought 10 years ago at Ikea, our new high-tech sleep solution feels like it’s light years ahead in terms of comfort and (of course) smart technology. And compared to my testing of other popular temperature-controlled sleep systems, I think Eight Sleep offers the best cooling mattress on the market today.

I certainly realize that what feels comfortable to me might not feel comfortable to you. So there is a chance that the Eight Sleep Pod mattress might be too firm or too soft for you. However, I think that Eight Sleep has struck a good balance that should accommodate most people’s preferences. 

The good news is if you like your current mattress, you can just retrofit it with the Pod 3 Cover and enjoy all the benefits Eight Sleep has to offer.

Medical Disclaimer

The information shared on this blog is for educational purposes only, is not a substitute for the advice of medical doctors or registered dieticians (which we are not) and should not be used to prevent, diagnose, or treat any condition. Consult with a physician before starting a fitness regimen, adding supplements to your diet, or making other changes that may affect your medications, treatment plan or overall health. MichaelKummer.com and its owner MK Media Group, LLC are not liable for how you use and implement the information shared here, which is based on the opinions of the authors formed after engaging in personal use and research. We recommend products, services, or programs and are sometimes compensated for doing so as affiliates. Please read our Terms and Conditions for further information, including our privacy policy.

20 thoughts on “Eight Sleep Bed Cooling System Review”

  1. I have a sleep number bed already and was wondering if the pro cover changes the comfort of the bed itself?

    Reply
    • Hi Anand,

      I don’t have first-hand experience with Sleep Number but I don’t think it would change the comfort because of how thin the Active Grid (cover) is.

      Cheers,
      Michael

      Reply
  2. Aren’t you afraid your cat will pop this with its claws?
    I have considered getting the Chili pad because you can get 1 side instead of the full cover which I think would reduce said cat claws puncturing it (since my body would block them somewhat). I do like the bells and whistles of the Eight cover though.
    Do you feel one cover has more padding than the other which would protect the tubing more?

    Reply
    • Hey Cara,

      Good point but so far, that hasn’t happened. We usually have a blanket or duvet on top of the mattress and so our cat hasn’t gotten a lot of opportunities to be directly on top of the mattress cover.

      Cheers,
      Michael

      Reply
  3. Hi Michael, thanks for the great review! I’m considering the Pod Cover since I already have a Casper mattress that I like. Are you aware of any differences? I didn’t find anything.

    Can you feel the water tubes, electronics, etc? I’m a side/stomach sleeper (and 190lbs) so I’m curious.

    Not sure where you live but here in Michigan it gets cold and our upstairs bedroom gets about 65 at night. Have you noticed if the room temp makes much of a difference now?

    Lastly, I do love having blankets on but have to kick them off because of being too hot. Are you able to keep blankets on with your Pod?

    Thanks again!

    Reply
    • Hi Matt!

      I haven’t looked at the Casper mattress but I know that a buddy of mine has and loves it. Besides being comfy, the Eight Pro mattress is CertiPur-US certified (not sure about the Casper). Everything else is pretty standard, I’d say.

      Regarding the topper, you can’t feel the tubes or sensor wires. I mean, if you probe with your fingers, you can probably make them out and you won’t feel them while in bed.

      We live in Georgia and our room cools down to about 66/67 at night. We haven’t changed that since we got Eight Sleep but I guess we could get away with a slightly warmer room if we wanted to.

      Regarding blankets — that was one of the reasons why we got the Pod Pro, I wanted to keep my blankets without overheating!

      Cheers,
      Michael

      Reply
      • Awesome, thanks for the reply! Glad to hear that you can’t feel the tubes! I’m assuming you use a mattress protector over it? I’m looking at the Pod Protector too though its pricey.

        Do you know if I give any features up by using only the cover and not the mattress?

        Thanks!

        Reply
        • Hey Matt,

          We have the following setup: Mattress > Active Grid > Sheet. That’s it. You won’t lose any features by going with the Pod Pro Cover only (as far as I know). All the smarts are in the topper (Active Grid).

          Reply
  4. That’s useful — both the difference in technique, and your experience with the two devices being congruent none the less. Thanks for running this to ground!

    Reply
  5. “The reason for those discrepancies is that Eight Sleep measures HRV during different times of sleep than WHOOP does.” WHOOP is supposed to measure HRV during deep sleep; when does Eight?

    Reply
        • Hi Mik,

          their PR department. This is what they told me: “HRV is measured throughout the night and we have a custom algorithm that converts continuous reading of HRV to a personalized baseline HRV that is useful to track on day to day basis.”

          Reply
          • So, sorry to be finicky, but they don’t actually say they only take readings during deep sleep — just “throughout the night,” correct? This would arguably not be as good as sampling during deep sleep, for reasons you’ve indicated.

          • Hi Mik,

            I confirmed that Eight Sleep measures HRV during different phases of sleep (not only deep sleep). That’s the reason why the scores I get from Eight Sleep vs. WHOOP are different. However, interestingly enough, both platforms show very similar trends!

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