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Eight Sleep Review: The Best Cooling Mattress (Based On 2 Years of Testing)

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Last Updated: Dec 01, 2022

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The Eight Sleep Pod is a temperature-controlled sleep system that my wife and I have been using since August of 2020. While my initial Eight Sleep review was based on the Pod Pro, we have since upgraded to the all-new Pod 3. As a result, this review reflects my experience with the Eight Sleep platform in general, as well as with the latest features of the Pod 3.

The purpose of the water-based heating and cooling technology built into the Pod is to help your body achieve and maintain an ideal temperature while you’re sleeping, thus increasing your sleep time and improving the quality of your sleep (more deep and REM sleep). This makes it more likely that you’ll wake up feeling fully rested and refreshed.

While the device can provide either a warmer or cooler sleeping experience, this review will primarily focus on the cooling aspect, which more closely aligns with improved sleep outcomes.

If you’re new to Eight Sleep, you should know that the Pod 3 is available in two versions, including the Pod 3 Cover and the Pod 3 Mattress. Both versions come with an “Active Grid” topper and a central command center called “The Hub.” However, the latter also includes a five-layer memory foam mattress.

Additionally, the Pod 3 by Eight Sleep has advanced sleep tracking technology built into the mattress cover, which the company calls the Active Grid. This technology layer can measure your heart rate, heart rate variability and other sleep-related biometrics.

I should mention that we own the entire system, including the mattress, and when the time came to upgrade from the Pod Pro to the Pod 3, we swapped out the mattress cover and hub but retained the mattress.

Eight Sleep Pod 3

Michael Kummer

The Eight Sleep System
Comfort
Ability to Control Bed Temperature
Sleep tracking
Value

Summary

My wife and I think Eight Sleep is the most comfortable mattress we’ve ever slept on, and I’m still excited every night when I go to bed and feel the cool surface of the mattress on my skin.

4.8

Continue reading to get answers to the following questions and more:

  • Why is staying cool while sleeping important?
  • What is the technology in the Pod 3?
  • How accurate is the Pod 3’s sleep tracking, compared to other sleep trackers?
  • What sleep issues can the Pod 3 help with?

I’ll also explain how my sleep has changed since I started using the Pod.

The Importance of Sleep (Quality)

Eight Sleep Pod 3 Review: The Best Bed Cooling Solution on the Market?
Watch my video review the Eight Sleep Pod 3, the latest version of the Eight Sleep system.

As I’ve said numerous times on this blog, sleep is the very foundation of your well-being. If you don’t sleep well, nothing else matters.

That’s why I’m protective of my sleep and follow a strict sleep routine.

A lot happens inside your body and brain while you sleep, and if you disrupt that delicate cycle you’ll suffer consequences, like the inability to focus, reduced mental and physical performance, increased risk of developing a metabolic disease and irritability, among others.

While sleeping well should come naturally (we don’t have to learn it), research suggests that many of us don’t get enough quality sleep. For example, I recently discovered a statistic from the CDC that claims that up to 44% of adults in the United States get fewer than seven hours of sleep per night

Additionally, about 70 million Americans suffer from sleep disorders, including insomnia, sleep apnea, restless legs syndrome or narcolepsy.

If you’re surprised by these numbers, just ask your friends and family how much sleep they get every night, and how rested they feel when they wake up. I bet most don’t get enough sleep or feel energetic in the morning.

Sufficient (quality) sleep is important for our well-being. So make sure that your bedroom is set up in a way that is conducive to sleeping well.

The Role of Temperature in Sleep Quality

How to Improve Your SLEEP (by Controlling Your Body Temperature)
You can learn more about the relationship between temperature and sleep in the video above.

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 melatonin in the evening and cortisol in the morning. 

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. In order to support that natural cooling-off period, it’s best to keep your bedroom temperature set somewhere between 60 and 67 degrees Fahrenheit.

Of course, if you only have one central HVAC unit (like we do), that means cooling down the entire house. Unfortunately, that leads to a lot of wasted energy.

Also, to fall asleep, your body’s core temperature has to drop by about two degrees. That’s one of the reasons why taking a hot shower before going to bed helps with falling asleep. As counter-intuitive as it might sound, hot water dilates the blood vessels in your extremities, increasing blood flow and thus helping your core to cool down more efficiently. 

What doesn’t help is having hot air trapped between the mattress and your covers — a situation that most of us can relate to.

I used to sleep hot, especially during the warmer months of the season, and often uncovered myself during the first half of the night. 

Of course, as my body temperature (and the temperature in the house) kept falling during the second half of the night, I would get cold and cover myself up again. That back and forth is obviously not conducive to a good night’s rest.

How I Like to Sleep

How cavemen sleep
Humans sleep best in a dark and cool environment.

I approach sleep similarly to how I approach nutrition — by trying to mimic the behavior of our Paleolithic ancestors. 

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. 

My idea of mimicking this environment is to cool down the room and remove as many artificial light sources as possible, and use a weighted or EMF-blocking blanket in addition to traditional bed covers. 

As a result, the “thin sheet” approach doesn’t really fit into that strategy, because it doesn’t reflect how humans have slept throughout evolution. By “thin sheet” approach I mean using only a thin sheet as a cover without any extra layers, such as a duvet or blanket.

But regardless of whether you like to sleep with a thick blanket or a thin one, your body temperature changes naturally throughout the night. And chances are that you’ll be too cold or too hot at some point.

Why We Chose Eight Sleep

Why we chose Eight Sleep
Both my wife and I are super happy with our Eight Sleep system.

While my wife and I were able to figure out how to make our room dark and cold, we’ve been struggling with controlling the temperature between the sheets and the mattress. As a result, we would often overheat in the middle of the night.

I sometimes exacerbated 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-caloric meal also 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 to better regulate my body temperature. At first, I was looking into so-called “bed fans” that would blow air under the sheets, but I wasn’t convinced they were the most practical solution.

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 Eight Sleep and they graciously agreed to send me their original Pod Pro for testing.

As I mentioned at the beginning of this article, 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.

Eight Sleep Pod 3 Review

Pros

  • Comfortable memory foam mattress.
  • Perfect bed temperature control with dual-zone support.
  • Cools down to as low as 55 degrees Fahrenheit.
  • Smart alarm that uses vibration and temperature to wake you up.
  • Reasonably priced (compared to regular premium mattresses).
  • Integration with Apple Health, Oura, Peloton and more.
  • Data-driven sleep and health coaching (via Span Health acquisition).

Cons

  • Sleep tracking is not always 100% accurate.
  • Adds more electronics to your bedroom.

Based on my research, Eight Sleep offers the most advanced “cooling mattress” and sleep technology on the market. While this review covers the entire Eight Sleep Pod — which consists of the memory foam mattress, the smart cover (Active Grid) and the Hub — you should know that you can retrofit an existing mattress with an Active Grid. Eight Sleep calls this the Pod 3 Cover.

If you do, most of the information in this review still applies, with the exception of anything that relates directly to the polyfoam mattress.

The reason we chose to go with the complete Pod was that our old mattress was already 10 years old and ready for replacement.

Unboxing and Smart Bed Setup

Setting up the Eight Sleep Pod was relatively straightforward and took only a few minutes.

Eight Sleep Pod Pro: Unboxing + How to Install
Watch my original Pod Pro smart mattress unboxing video!

Something worth pointing out is that the Pod 3 ships as two separate packages that likely won’t arrive on the same day. We received a box with the memory foam mattress first, and the Active Grid and Hub arrived a few days later.

Once you’ve received the complete shipment, you should unbox the mattress first by carefully cutting away the plastic wrapping. Just make sure you don’t cut into the mattress!

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.

The next step includes zipping on the mattress cover (the Active Grid) and routing the cable along the headboard of your bed to where you intend to position the Hub. 

Once that’s complete, you can find a good spot for the Eight Sleep Hub and plug in the water connections, the USB cable 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 Wi-Fi 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 the 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 (to help prevent mold or other microorganisms from growing inside the tubes). 

Eight Sleep Pod 3 Mattress

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

I think it’s fair to say that everybody wants to sleep comfortably. Unfortunately, the definition of “comfortable,” and how that translates into the firmness of a mattress, differs from person to person.

Both my wife and I prefer softer mattresses, because we’ve found that harder mattresses cause pressure points. We noticed that the last time we went to visit my family in Austria and stayed with my mom and her husband; the bed we slept in had super-firm mattresses that made us feel like we were sleeping on the 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 12-inch hybrid mattress is made with five comfort layers of CertiPUR-US-certified foam and has an ideal “medium” firmness for providing contouring support and decent edge 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 Eight Sleep 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, Eight Sleep is 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.

Temperature Control

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

The ability to control the temperature of the mattress surface was the feature that most attracted me to Eight Sleep.

To facilitate that temperature control, the Active Grid has soft water tubes (made from silicone) sewn into the fabric, enabling the Hub to circulate water through those tubes at the desired temperature.

It’s worth noting that you can control the temperature of either side of the mattress individually. That’s great, because my wife likes to sleep a tad warmer than I do. 

As far as the temperature range is concerned, you can set it 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. 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 optional 8+ Pro subscription, which I’ll discuss later) that can automatically adjust the temperature settings based on my sleep history and changes in the environment (e.g., room temperature).

As I mentioned at the beginning of this review, your body temperature naturally changes over the course of the night. Additionally, your temperature perception can vary based on 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 to learn from your environment and make smarter temperature recommendations. Additionally, you can set different temperature settings for the various stages of your sleep, including:

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

In practice, the Pod starts cooling down (or heating up) your mattress about an hour before your set bedtime. As you fall asleep (i.e., during the initial sleep stage), the Pod 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.

As your body starts naturally cooling down during the second half of the night (the time when most REM sleep occurs), the Pod can slightly increase the temperature of the mattress surface before cooling down or heating up the mattress to encourage you to get out of bed once you’ve woken up.

Of course, you can control all four temperature settings individually based on your preferences.

Overall, I think the incredibly wide temperature range offered by the Pod 3 should be able to accommodate most users. For those extra “hot” sleepers, Eight Sleep offers the Pod 3 Max, which includes a special 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 Fahrenheit might not be cold enough (the lowest the Pod 3 can go), you might want to consider getting the Pod 3 Max instead. The special fabric I mentioned above improves airflow and reduces the chances of hot air getting trapped around your body.

Autopilot (8+ Pro)

If you subscribe to the optional 8+ Pro membership ($19 per month), 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 Pod.
  • 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 me how the temperature settings felt the night before (i.e., if I was too hot or too cold during the various stages of sleep). Based on that feedback, along with the other factors the system takes into consideration, Autopilot can continually learn how to adjust my bed temperature to further improve my sleep.

Sleep Tracking

Eight Sleep - More Deep Sleep with Lower Temperatures
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 (both are 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 Active Grid 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 Active Grid’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.

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, a 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 bed might not always accurately detect if you’re sleeping or trying to fall asleep. We’ll talk about those “assumptions” in more detail further down.

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 from my WHOOP Strap.

In other words, both platforms confirm that I spend approximately 40% of my sleep in those restorative phases. That’s an ideal amount for a healthy adult.

However, the Pod 3 might not always be able to accurately differentiate between light sleep and being awake, which could lead to a lower sleep score in the mobile app (see below for more on that).

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.

While 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.

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 wake-up 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. For example, 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 Pod should only trigger the alarm if 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, so I probably won’t use the smart alarm much except on days where I have an early flight or an appointment I can’t be late for. In most other cases, I’ll allow my body to get as much rest as it needs without worrying too much about the exact time I roll out of bed. 

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 wake-up times and customize the smart alarm settings.

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 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). What I like about this section of the app is that it offers a visual indication of whether your sleep consistency is within the 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 because it can help you improve your sleep consistency. However, as I mentioned above, the rating system might not work perfectly for everybody.

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 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 % 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 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. 

What I like about the app is that it not only shows you 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 (8+ Pro)

Sleep Tools are part of the 8+ Pro subscription
Sleep Tools are part of the 8+ Pro subscription.

The last section of the app consists of sleep tools that are part of the paid 8+ Pro subscription. It includes Autopilot to train your Pod and 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.

Except for Autopilot, I haven’t fully explored this section yet but I have it on my to-do list.

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. Think of it as the WHOOP Journal, but with human involvement.

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 introduced “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 still somewhat limited, and the correlations aren’t quite as in-depth as the ones the WHOOP Journal offers, 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

I prefer abstract temperature settings instead of the actual numbers
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.

Price

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

SystemFullQueenKingCali King
The Pod 3 Cover$2,095$2,195$2,395$2,395
The Pod 3 Mattress$3,095$3,395$3,795$3,795
The Pod Pro 3 Max$3,695$3,995$4,395$4,395

As a reminder, the Pod 3 Cover doesn’t include a mattress but is meant for retrofitting any 10 to 11-inch mattress, and the Pod 3 Max 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 to 16-inch mattress.

As you can see, the 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 can sign up for the optional 8+ Pro membership that costs $19 per month and unlocks additional features, such as Autopilot, sleep tools, and digital coaching and data insights (see the FAQ section below).

Check Price

If you’d like to give Eight Sleep a try (note that you have 100 nights to try the system and send it back if you don’t like it), make sure to use the link above and enter coupon code KUMMER at checkout — it’ll save you $300 off the purchase price of the Pod and $150 off the Pod Cover.

How Eight Sleep Has Changed How We 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, and if you’re on a budget, you might be wondering if the Pod 3 is worth the extra money. Similarly, if you own the Pod 2 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:

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

To summarize, the Pod 3 features improved sensor technology that facilitates advanced biometric tracking. Plus, support for 5 GHz Wi-Fi 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 Mattress and the Pod 3 Mattress 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 Wi-Fi 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.

How Does the Pod 3 Compare to Similar Sleep Products?

Eight Sleep vs. Chilisleep [Comparison of Top Bed Cooling Systems]
Watch my YouTube video comparison of Eight Sleep and Chilisleep, a popular Eight Sleep alternative.

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.

With regard to Cube Sleep, it’s important to remember that bed fans 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. Eight Sleep can reduce the temperature of the mattress surface to 55 degrees Fahrenheit and keep it there, without making any disturbing noise.

Frequently Asked Questions

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 since Eight Sleep will cover the return shipping fees, you have literally zero risk.

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?

Overall, Eight Sleep’s high-density foam mattress absorbs most body movement. I asked my wife the other day, and she said that as long as I don’t let my body (literally) fall into bed, she doesn’t feel me moving.

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 Than 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 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 lies on her side or stomach. Neither of us has had any issues as far as support or comfort are concerned. 

What warranty does Eight Sleep provide?

The polyfoam part of the smart bed is covered by a 10-year warranty. The technology layer is covered by a two-year limited warranty. For more information, check out Eight Sleep’s warranty page.

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.

Can you purchase the Pod 3 without the mattress?

Yes, you can purchase the Active Grid separately! Eight Sleep calls this product the Pod 3 Cover and it zips on to any 10″ to 16″ mattress.

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

Neither the Eight Sleep mattress nor the Active Grid cover emits EMFs — only the Hub (the device that sits next to the bed) emits EMFs. However, it’s an extremely low amount of EMFs 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.

What is the 8+ Pro membership?

8+ Pro is an optional subscription service that adds a suite of digital sleep improvement tools to the Pod experience. Specifically, the 8+ Pro subscription adds the following features: temperature Autopilot, digital coaching, data insights, sleep content and discount on accessories and upgrades.

What is the difference between the Pod Pro 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.

Does the Pod 3 come with an improved mattress?

No, as far as I can tell, the Pod 3 mattress is exactly the same as the previous model. In other words, it’s made from the same materials and has the same number of foam layers.

Is Eight Sleep loud?

The Eight Sleep Pod 3 is incredibly silent. In fact, the only time you can hear the system is when it starts cooling — but even then, only when it’s completely quiet in the room and you’re actively listening. In other words, unless you know what to listen for, you won’t hear it and it won’t bother you.

Eight Sleep Review: Final Verdict

The Eight Sleep System
The complete Eight Sleep system consists of a memory foam mattress, an Active Grid topper and a central control unit.

It’s been two years since we got the Eight Sleep Pod 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. 

For us, Eight Sleep is the most comfortable mattress we’ve ever slept on, and I’m still excited every night when I go to bed and feel the cool surface of the mattress on my skin.

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.

18 thoughts on “Eight Sleep Review: The Best Cooling Mattress (Based On 2 Years of Testing)”

  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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