by Josh Teder

Introduction and Overview

It’s been 6 months since I got an Eight Sleep Pod 4, and in that time, yes, my sleep has improved without a doubt, especially in the warmer months. But are the clear benefits of having a liquid-based temperature control smart cover for your bed outweighed by this product’s price, subscription model, and downsides? After spending 6 months with this thing, I think I know the answer.

How the Pod 4 Works

First, let’s start with the highlights, and the main one that I found with the Pod 4 that Eight Sleep sent me is that it allows you to sleep cool. Depending on your ambient room temperature, the Pod 4 can cool your bed to as low as 55° F (or about 13° C) and heat it up to 110° F (or about 43° C), though keep in mind the bed can only heat or cool about 20° warmer or colder than your ambient room temperature.

It does this with two main components: The Hub and the cover. The Hub looks like a small tower PC and acts as both a computer and solid-state heat pump. You fill it with water during setup to prime the cover, which has tubes laced throughout it. These tubes circulate water through what Eight Sleep calls the Active Grid, then brings it back to the Hub, which acts as a solid-state heat exchanger which works like a Peltier device or thermoelectric cooler. The fans at the back of the unit likely cool off the junction where the heat is conducted, as well as the electronic components, which is why you’ll feel slightly warmer air passing out of it when the unit is running.

Temperature Control and Comfort Features

Now you might be wondering about noise, so let’s take a listen to it. I’ve never been bothered by it, and it’s right next to where I sleep. So how well does the cooling and heating actually work? Extremely well. The best example I can give of this is typically I take showers at night as I’m getting ready for bed, and before I got the Eight Sleep, I would usually just kind of walk around and not get into bed right away because I was still hot from my shower, and I didn’t want to just radiate heat back into my mattress. With the Eight Sleep, what I notice is I can take my shower, get ready for bed as normal, but then get right into bed. When you do that, you’ll start to just feel the mattress cover pull away the heat from your body. It’ll first start at your legs and then go through up your torso, and as it does that, I find that I often start to get tired and sleepy, and I fall asleep.

This is what the Eight Sleep system does so well – it can get your body to a temperature better for sleep much faster than a fan or other air cooling system could because using a liquid is a much more efficient way to transfer heat. Now, there is a bit of an adjustment period when you first start using it. I initially set mine up too cold, but thankfully the Pod 4 has sensor areas on both sides of the cover where you can triple tap to turn the temperature up or double tap to turn it down. This makes it easy to adjust the temperature while you’re still in bed, preventing you from having to get up and go grab your phone, or even worse, having to keep your phone on your bedside table just to be able to change the temperature of the bed like previous versions of the Eight Sleep actually basically forced you to do.

The cover initially had a slight factory smell, but that dissipated over the next week, and I no longer notice it. Another thing that took some getting used to was waking up to the bed getting warmer in the morning. The thinking with this feature is instead of getting woken up by some annoying alarm, you’ll just naturally start to wake up as your bed changes in temperature. The Pod 4 also has an optional vibration alarm, which I really like. In my experience, these alarms have worked well, though it’s become a bit more of a struggle in winter months because you wake up to the bed warming, and then you’re in a warm bed, and it’s cold out of the covers, and you do not want to get out of bed. So in the winter months here, I’ve actually readjusted this feature to actually cool the bed down in the morning so then I will want to get out of the bed into a warm shower.

Now before getting the Eight Sleep, one of the main issues I was having with my own sleep was I’d often find I’d wake up in the middle of the night kind of hot. I’d throw off my duvet cover and then just decide to sleep with a top sheet, but then it was already kind of warm, and it would take forever to get back to bed. Sleeping with the Pod 4 has largely prevented this issue from occurring, and when it does occasionally happen, I’ll just adjust the bed a bit cooler, and I notice it’ll help me drift back to sleep pretty effectively – unless I accidentally had caffeine too close to bedtime. Unfortunately, not even a liquid-cooled mattress cover is going to be able to solve that issue for you.

And yes, when traveling, I definitely noticed a difference in my sleep. Other mattresses felt warmer, and I didn’t stay asleep as well as with my Eight Sleep. Oh, and when you’re away from bed, the Eight Sleep app has a really nice away mode that you can use when traveling. You simply select a return date, and your bed will stay off until then, with metrics paused until you get back.

Sleep Tracking and Data Analysis

Another big feature with Eight Sleep is sleep tracking. The Pod 4 tracks your sleep stages, heart rate, HRV (heart rate variability), respiratory rate, and even your toss and turns throughout the night through sensors embedded in the Active Grid. Generally, I found the tracking to be pretty accurate. It definitely seems more accurate than the tracking on my smart watches, though there have been periods where I have been awake in bed and just not moving around a lot, and I do notice the Eight Sleep not picking that up, and then I’ll have to go back into the data and add that in manually. But generally, it has registered my times awake in the middle of the night as well as my wakeup time correctly.

Now Eight Sleep tracks this data for two main reasons. One is to give you data on your sleep as well as help you create healthy sleep habits, like going to bed and waking up at the exact same time every day. The app overall is very slick and well-designed. I love being able to go in and see my sleep data and add in tags so if I knew I drank alcohol, had caffeine late in the day, or used melatonin at night, I can add that extra info in, and it also helps reinforce the association between these activities and how well or not well I slept. They even had a 2024 Year in Sleep Review that shows how well I slept compared to peer men in my age group in my state, which was certainly an interesting thing to create with all of the data that they collect.

The Autopilot System

Now the second reason it tracks this data is to help power their Autopilot system. Autopilot will automatically adjust your bed’s temperature throughout the night depending on the stages of sleep you’re in, and if it notices, for example, you didn’t get enough REM sleep the night before, it actually adjusts the temperature to try to keep you in REM as long as possible and rack up the amount of time you spend in REM during that night’s sleep. Autopilot makes real-time adjustments to improve your sleep quality based on your preferences, sleep history, biometrics, wakeup time, and bedroom temperature, sleep stages, and even local weather.

You can review your Autopilot recap each morning to see exactly what adjustments were made and when, and if you bought the Pod 4 Ultra, which comes with an adjustable base, Autopilot can also mitigate snoring by slowly raising the elevation of the bed until you stop snoring and then lower the bed back down. Does Autopilot make that much of a difference? Uh, 6 months later, I’m not actually sure of that honestly. I think the main benefit of this product is that it can keep you cool at night, which is critical for better sleep, but I haven’t been convinced that the Autopilot technology itself is the reason for that. The peer-reviewed study on Eight Sleep’s website doesn’t mention Autopilot at all, and most if not all of the claims made on Eight Sleep’s website about sleeping better can just be linked to being able to make your bed sleep cooler, not necessarily because Autopilot is making 0.5-degree adjustments throughout the night.

Now another situation I think the Eight Sleep is great for is actually when you’re sick. I had COVID during my testing period, and when I was feeling hot with a fever or then getting chills, being able to adjust its temperature throughout the day to what felt comfortable was really nice.

Design and Setup

Another highlight of the Pod 4 is its design. The cover is easy to put on your existing mattress, and my sheets fit over it fine. The Hub isn’t larger than a desktop PC, so I could easily fit it in between my bed and nightstand. On the back of the Hub, you’ll find the connection for the hose from the cover and a USB-A port for the data connection to all the sensors in the cover. The end of the hose also houses a new filter which you’ll need to replace every 6 months. If you subscribe to Autopilot, they’ll automatically ship it to your address. The system setup didn’t take too long, especially now that the Pod 4 system can prime the cover way faster than previous models – it only took me about 10 minutes, whereas it would have taken me about over an hour with a Pod 3 system.

Product Downsides

Now let’s talk about the downsides I found with the Eight Sleep Pod 4. First is how the cover affects the feel of your mattress – it makes it more firm, and over time, I have noticed the grid more and more, and as a side sleeper myself, I would notice throughout the night sometimes I’d get in a position where I’d be like laying on my arm or sticking it out too much, and the grid plus my mattress just seemed to aggravate and put pressure points on some of my tendons. However, I recently rotated my mattress, which did help with some of the issues I encountered at the end of my testing period, though you can still clearly see in the cover little dips from where you can tell my body weight just over time has pressed into the cover.

Subscription Model and Warranty

The biggest downside of the Pod 4 is the Autopilot subscription. Now yes, there are costs associated with keeping all of your sleep data stored in the cloud, but given that the Hub is basically the size of a tower computer and does have some computing capability, there’s no real reason why they couldn’t ship it with local storage for that sleep data. If you want to have your sleep data backed up to the cloud or you want to have the latest Autopilot algorithm, like yeah, sure, sell that via subscription, and yeah, maybe I would subscribe to it, but that’s not the model Eight Sleep has gone with here. Features like scheduling your bed’s temperature, setting thermal alarms, storing your sleep data, and even making Autopilot adjustments are available only with a yearly subscription.

Now Eight Sleep didn’t used to have all of these features behind a paywall – they moved them behind the subscription paywall in early 2023, and in doing so, they made it much harder to recommend their products. The warranty situation is also a bit concerning. You get one year for the Pod cover and two years for the Pod itself. The $25 a month Autopilot subscription extends this to a 5-year warranty, with the $15 monthly subscription paid annually bumps it up to 2 years. For a product that costs $2,800 that you fill with water and goes on your mattress, a one-year warranty doesn’t really inspire that much confidence in how long Eight Sleep thinks it’ll last before leaking, which yes, can happen, and you’ll find various posts about it happening on the Eight Sleep subreddit. However, in my six months of testing, I have not had any issues.

Final Verdict and Recommendations

So after 6 months with the Eight Sleep Pod 4, do I recommend it? Um, it really depends on how much you value your sleep, honestly, because yes, this product can fix specific sleep problems people have. Like for me, I no longer consistently wake up in the middle of the night feeling hot, throwing off my duvet cover. For around $2,800 with a $200 yearly subscription, which is required for the first year, based on my experience, I’d probably pay that just because of the better sleep I’ve gotten. In fact, in 6 months, I haven’t had a single night of waking up with night sweats. Even when I had COVID, I’ve been able to sleep with my duvet, my waffle weave blanket, as well as a top sheet all year long, which that’s never happened before, honestly. I’ve just never slept better.

But let me be clear: from a consumer standpoint, I hate this subscription model. It completely rewrites the consumer expectations around basic product functionality. It comes across as if some bloodthirsty venture capitalist-filled board fired the CEO and replaced them with the BMW person who invented the infamous seat heater subscription. Paying to unlock functionality that is already built into hardware currently sitting in your home is – it just feels like they’re trying to nickel and dime their customers who already spent a good amount of money on this product, and it just cheapens the experience. I’d much rather pay once for this thing, maybe at a slightly higher price, but have all the functionality forever plus a longer warranty.

Now I should again mention that Eight Sleep provided this unit for testing, but I am planning to move in the new year and get a larger bed for my partner and I to sleep on. Will I likely be buying one with my own money? Probably, but I’ll definitely look around at the competition as well. There are other companies out there like ChiliPad from Sleep Me, BedJet – though none of them seem to be as good or effective as the product that Eight Sleep has built, as I’ve researched the competitive landscape so far.

Now another question you might have about this entire product category in general is: is this just a solution to a problem of our own making? With the popularity of foam mattresses that, no matter how they market them to you, all foam mattresses for the most part are going to retain some amount of heat. I think there’s some truth to that, but you also have to consider your bedding that can keep you too hot at night as well.

So do I recommend the Eight Sleep Pod 4? Look, I’d recommend these types of products to anybody who thinks they could benefit from having a bed that sleeps cool or even warm if you’re in a really cold climate, and a bed that can keep different temperatures on different sides of the bed for different sleep partner preferences – you and your partner can have completely separate sleep tracking and temperatures for each side of the bed. Only one of you has to pay for the subscription, which is a plus, I guess.

The Eight Sleep Pod 4 is one of those products that after using it for 6 months makes me wonder how I ever lived without it. However, the company’s subscription pricing strategy is just a complete turnoff. I hope Eight Sleep comes to their senses and readjusts what features just come with the product versus are part of the Autopilot subscription, but until then, I can’t give it my full recommendation. The product itself works and works well but is unfortunately overshadowed by the company moving basic functionality behind a yearly subscription.

To check the current price of the Eight Sleep Pod 4 system, learn more about the product, the Pod 4 Ultra which can mitigate snoring, and more, check out the blog post for this video at 6monthslater.net. And if you want to see more of my popular reviews like my review of the Apple Vision Pro or Meta Ray-Ban smart glasses, you can get to those videos by clicking on the cards here. And if you have an Eight Sleep Pod 4 or previous version, let me know what you think of it. How has it held up, and would you buy it again? Let me know down in the comments. For 6 Months Later, I’m Josh Teder. Thanks for watching.