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“I would be dead without the Eight Sleep,” my boyfriend Kyle announced recently.
He may have a point—at least when it comes to us not killing each other from sleep deprivation. Forget cutting out alcohol, limiting screen time, taking magic pills, sacrificing your first born to the serotonin gods, and whatever other sleep hacks you’ve tried. The Eight Sleep Pod 4 has single-handedly turned me from a certified Terrible Sleeper into a Sleep Champion. And while I’m not one to conflate correlation with causation, running hasn’t felt this good since my early 20s.
Eight Sleep what now? The Eight Sleep Pod 4 is like Silicon Valley waved a magic wand over your Norwegian grandmother’s electric mattress topper while singing “bippity-boppity-boo!” That is to say, it’s a temperature-regulating mattress cover with all the bells and whistles you could ever want and then some. It can heat or cool each side of the bed manually or automatically based on smart sensors that monitor things like restlessness, time awake, and snoring.
In our lives, there is now only BES (Before Eight Sleep) and AES (After Eight Sleep). And no, I am not being paid to say that. BES, summer showed up with zero chill, quite literally, to our hometown of Boulder, Colorado, this year. The average high that month was an unwelcome 88 degrees, with the nights barely dipping below 60. Sleeping in our unairconditioned second-story apartment could have been a patented form of torture.
Going to bed hot sprawled out on top of the covers, I’d wake up in the middle of the night cold and pull the covers over me—only to fall asleep and be rewoken from sweat dripping down my back. Hot, cold, hot, cold, hot, cold, each night felt like a never-ending dance to Katie Perry in the inner circle of hell. Brief moments of unconsciousness were often shattered by Kyle restlessly kicking his legs like he was frantically swimming away from Jaws over on the other side of the bed.
My sleep and health metrics reflected this nightly nightmare. It takes more than one hand to count the number of June mornings I woke up to the silent alarm bell of a drenched t-shirt and a splitting headache. In case I couldn’t already tell, my Oura ring also told me I wasn’t getting the recommended one to two hours of deep sleep a night. I was too busy spending at least an hour (sometimes many more than that) restlessly tossing and turning.
Boo hoo, cry me a river little Abby wasn’t sleeping good, I know. But this is a review for a $2,600 mattress cover, what did you expect? If you, too, live without central air in an apocalyptic region of the world tormented by temperamental weather, then you know the drill. I longed to get out of town and sleep in an air conditioned hotel room, no matter how hard the bed; get attacked by mosquitoes under the open skies in the mountains; or be smooshed between ear-curdling screaming babies on an airplane—anywhere cooler than in our 600-square-foot inferno.
That is, until our knight in a black case, the Eight Sleep Pod 4, arrived at the end of June. Like dumping ice water on your head in the middle of a hot race, the effect was immediate. After sleeping on our Eight Sleep for four and a half months and through two seasons, I’m finally ready to tell you whether it’s worth the $2,600 price tag.
Why Eight Sleep?
If you’ve heard of Eight Sleep, you probably know it’s backed by numerous celebrity endorsements. What you may not know is that it’s been quietly purchased by numerous Olympians—some of whom went to the lengths of bringing their Eight Sleep with them to the Paris Olympic Games this summer. But there are a fair number of temperature-regulating mattresses and mattress toppers on the market. Everything from memory foam toppers that (theoretically) uniformly cool the bed thanks to heat trapping materials (these will cost you about $200-$300), fan-powered toppers ($1500-$2000), and cooling bed “systems” like Eight Sleep.
While I run hot, I don’t run nearly as hot as Kyle. Hence, I wanted a solution that would a) be effective enough to actually cool down the bed and b) provide dual-temperature control so we could both sleep comfortably. That immediately ruled out the first two categories. And when it comes to bed cooling systems, there aren’t that many options to choose from. But they are all in the same price range, so if you choose: consider this review more of a review of the bed cooling system concept than the product itself. Eight Sleep also offers the Pod 4 Ultra, which for nearly double the price ($4,500) comes with a dual-controlled bed frame that can be manually and automatically adjusted up and down. We’re not quite that fancy.
What is the Eight Sleep Pod 4?
The Eight Sleep Pod 4 is physical proof that dark magic exists. But really, it’s a mattress cover with a web of rubber tubes and sensors covered by a soft fleece black topper. It’s very comfy, and you don’t feel the tubes or sensors at all. Like a fitted sheet, it’s elasticized for a snug fit over your mattress. Kyle put it on the bed with no snafus while I was away.
The mattress connects to a black box about the size of a large shoe box called the hub, which controls both sides of the mattress individually based on your personal preferences, sleep stage, and the ambient temperature. To set it up, you simply add water up to the indicator line in the hub and snap the lid back on. (We have yet to experience a leak or any other type of malfunction, although there is a five-year warranty.)
Once you’ve set your Eight Sleep up, the fun begins:
Temperature Regulation
You can adjust the temperature of both sides of the mattress separately on a sliding scale of -10 to +10 (55 degrees to 110 degrees Fahrenheit) in one-level (roughly 2.75-degree) increments. That range is more than enough to let you maintain that “cold sheets” feeling all through the night, to the equivalent of a bedtime ice bath. Even on the hottest, muggiest summer nights I found myself legitimately cold at -4. (Kyle tolerates -10, but I wonder if that’s simply a personal challenge he’s set for himself.)
Sleep Stage Customization
Your body temperature fluctuates throughout the night—something Eight Sleep has accounted for. The Eight Sleep app lets you preset four temperatures throughout the night: bedtime, early, late, and wake time (which includes a thermal and vibrational alarm, if you so choose). In summer I liked to start off cold (-4) and work my way up to slightly warmer throughout the night (-3 or -2). Now that it’s almost winter, I’ve set my side of the bed to start off with a “warm sheets” feeling at +2 or +3, dip down to -1 once I fall asleep, and then come back up to +1 or +2 when it’s time to get up. Yes, I am officially sleep spoiled.
The sensors on the bed also know when you crawl in for the night, when you fall asleep, when you wake up, and when you get out of bed, doing all the sleep-stage adjusting for you as well as turning the mattress cover on and off without you needing to think about it.
App-and Tap-Controlled
But of course, those presets are just the start. You can adjust the temperature at any point via the app. But who wants to look at a bright phone screen in the middle of the night? Not the good folks at Eight Sleep. The Pod 4 lets you manually adjust the settings by tapping the side of the mattress: two taps for one level colder, three taps for one level warmer.
The Eight Sleep Pod 4 is also smarter than you, and in my experience 90 percent of the time it does all the adjusting you need while you are deep asleep. Let me explain.
This is Your Autopilot At Your Service
This would not be a tech review in 2024 without talking about Artificial Intelligence. While I remain an AI skeptic, I will admit that Eight Sleep proves AI can actually add value to our lives, sometimes. Enter autopilot, Eight Sleep’s “smart” system that uses user data such as biological sex and age, as well as biometric data collected from sensors on the mattress itself, including heart rate, respiration rate, and chest vibrations, and environmental data like ambient temperature and humidity level to automatically make micro-adjustments to the mattress temp on your side of the bed to keep you fast asleep.
You can turn autopilot on and off. I tried sleeping without it once and I’m sorry to inform you that the difference was stark—I woke up hot or cold several times throughout the night. Turns out those automatic micro-adjustments make a big difference in regulating your body temperature while you’re asleep.
In Data Eight Sleep Trusts
In addition to helping you fall and stay asleep through its smart temperature regulation, autopilot includes a host of sleep and health tracking measures, including heart rate variability (HRV), resting heart rate, respiratory rate, and time spent in deep sleep, REM sleep, light sleep, total time asleep, and snoring. Cross-referencing this data with my Oura ring, the two seem to be in very close alignment, with Eight Sleep providing slightly more generous sleep metrics (e.g. if Eight Sleep gives me a 98 sleep score, Oura ring will give about a 92).
Admittedly, I don’t care a ton about this data (despite also wearing an Oura ring, but that’s because I’m taking this review seriously!). Stressing about my sleep quality every night would stress me the hell out and ensure I don’t sleep at all, perfect temperature be damned. But I like looking at trends and cross-referencing them with my training and life stress to inform my running. I’ve also found HRV and resting heart rate to be pretty good indicators of when I’m getting sick, and flagging that early has helped me dial back my training in time to mitigate falling into the deepest of deep holes.
Speaking of getting sick, this summer I got the gift of Covid-19 quickly followed by a stomach bug. Both times, my HRV and resting heart rate numbers from Eight Sleep were elevated beforehand, during, and as I recovered, and I used those metrics as a loose guide to inform me when to rest and for how long. (The stomach bug felt like it knocked me out way harder than Covid, and my HRV, resting heart rate, and respiratory rate supported that to be true.)
In fact, the stomach bug was the sickest I’ve been in at least a decade. Flutter in and out of consciousness, overcome with nausea, full-body-burning sick. I didn’t leave my bed for several days. And despite a 101 degree fever, I didn’t sweat through my shirt. Both during the day and through the night, Eight Sleep kept me as comfortable as possible when you can’t concrete hard enough to watch the Olympic marathon playing on a screen five inches from your eyes.
OK But What About Winter?
I was over being overheated this summer, it did not even occur to me that our Eight Sleep would be beneficial during winter. That was a gross oversight. Now that nights are dipping below freezing, I’ve started setting my side of the bed to be warm (+2 or 3) when I get into bed—no more crawling into bed with fleece socks, sweat pants, a sweatshirt, and a beanie needed—before cooling the bed down to -1 when I fall asleep, and then up to 0 when it’s time to wake up.
Turns out, it’s really helpful to your sleep when you don’t spend the whole night peeling off layers one-by-one as you warm up. Meanwhile, Kyle can continue to have his side of the bed stubbornly set to -10 without interfering with my hygge paradise at all.
Like in summer, the temperature range for chilly nights is more than enough: I’ve found that anything above +4 makes me sweat.
Is the Eight Sleep Pod 4 Worth the Price Tag?
I have no stake in the game of selling you on this thing. All I will say is this: of all the sleep remedies I’ve tried (which, as a consistently bad sleeper since babyhood, is many), Eight Sleep is more effective for me than all of them combined. In addition to Kyle’s verbal endorsement, he’s stopped ripping up the covers and pushing them into a jumbled pile on my side of the bed during the night, a win-win for us both.
I spent over a month away from Boulder at the end of the summer, and the contrast in my sleep quality was alarming—even though I was generally sleeping in cooler places, often with air conditioning. The effect of getting cooled (or now that it’s fall-bordering-on-winter, warmed) from underneath just seems to be so much more effective than from above. You can still enjoy the comfort, security, and warmth of being cozy in the covers without any of the negative consequences, such as boiling to death. And these sensations provide very real effects, including a release of “feel-good” chemicals like dopamine and serotonin, which in turn help you relax, lower stress, and…da da da…help you sleep.
At $2,600 plus a $17 monthly fee for autopilot, the Eight Sleep Pod 4 is obviously a luxury product. (It would be number one on my wedding registry, and if I was rich I would be gifting one to every member of my family for the holidays.) But it’s also a luxury solution to one of the most vital components of not only our running, but our lives. Other than effectively regulating your temperature, you wouldn’t know you’re sleeping on anything other than your bed. The unit is very quiet. In fact now that I don’t need an industrial fan blowing on my face to fall asleep, I haven’t enjoyed sleeping in an environment that is this quiet maybe ever. And the automatic temperature regulation actually works.
I would make do without the sleep tracking data and health metrics. I would survive without autopilot, although I would prefer not to. But I cannot go back to living without a bed temperature-regulating sleep system. Kyle and I could be spending $2,600 every year on supplements, fans, fancy sheets, blue-light glasses, hypnosis, central air conditioning, and a whole host of other sleep-saving measures—and they wouldn’t be half as effective.
The only downside, minus the cost?
I never want to leave the house again.
Eight Sleep Pod 4
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