What heatwave? This water-cooled mattress topper beat the heat, hormones, and hot flushes

If you spent the recent heatwave tossing, turning, and kicking off the duvet only to wake up tangled in it again three hours later, you're not alone. While everyone else was desperately opening windows, pointing fans at their beds, and Googling whether sleeping with frozen water bottles was actually safe, we were testing something altogether more futuristic: the Eight Sleep Pod 5. This smart mattress cover promises to actively cool (or warm) your bed throughout the night, creating what is essentially a climate-controlled sleeping environment.

As someone who regularly tests the best mattress toppers, I've seen plenty of products claim they can transform your sleep. Cooling pillows, temperature-regulating duvets, breathable mattresses they all help to some extent. The Eight Sleep Pod 5 takes a completely different approach. Rather than relying on specialist materials alone, it uses water-powered temperature control and sleep-tracking technology to adjust your bed's climate while you sleep.

For women navigating hot flushes, night sweats, or simply wondering how to sleep in the heat, that sounds almost too good to be true. So when our tester, Sally, spent several weeks sleeping on the Eight Sleep Pod 5, I was keen to find out whether this high-tech sleep system could genuinely deliver cooler, more comfortable nights. And whether it's worth its eye-watering price tag.

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Eight Sleep Pod 5 Cooling Mattress Topper review

• RRP: £2,699
• Sizes: UK double, UK king, UK super king, UK emperor
• Materials: polyester, rayon, nylon, bamboo
• Temperature range: Cools to 12ºC or heats to 43ºC
• Zones: dual controls
• Alarm: vibration and/or thermal
• Machine washable: no
• Trial: 30 nights
• Warranty: 5 years

What is the Eight Sleep Pod 5 Cooling Mattress Topper?

The Eight Sleep Pod 5 isn't really your standard mattress topper, nor is it a cooling mattress in its own right. Instead, it's a smart cover that sits around your existing mattress, turning it into a temperature-controlled sleep system. Hidden inside the cover is a network of tiny tubes through which water is circulated, allowing the Pod to heat or cool your side of the bed to a precise temperature. A separate hub, which sits discreetly beside the bed, does the hard work behind the scenes, pumping water through the system and making automatic adjustments throughout the night.

What sets the Pod 5 apart from traditional cooling bedding is that it actively responds to your body rather than simply trying to dissipate heat. Using built-in sensors, it tracks factors such as your sleep stages, heart rate, breathing rate, and body temperature, then tweaks the climate of your bed accordingly. If you tend to wake up drenched in sweat at 3am or find yourself piling on extra blankets before dawn, the system is designed to react before you even notice you're uncomfortable. Everything is controlled through the Eight Sleep app, where you can set your preferred temperature and view detailed sleep insights each morning.

Who would the Eight Sleep Pod 5 Cooling Mattress Topper suit?

The Eight Sleep Pod 5 will appeal most to anyone whose sleep is regularly disrupted by temperature. That includes hot sleepers, couples who can never agree on whether the room is too warm or too cold, and women navigating perimenopause or menopause. One of the standout features is its dedicated Hot Flash Mode, which uses the Pod's sensors to detect sudden changes in skin temperature and automatically cool the bed in response. Rather than waking up overheated and throwing off the covers, the idea is that the Pod reacts before a hot flush has the chance to fully disturb your sleep.

It's also worth noting that Eight Sleep includes a Pregnancy Mode, designed for those experiencing the temperature fluctuations that often come with pregnancy. Combined with the ability for each partner to choose their own sleep temperature, it makes the Pod 5 is particularly well suited to life stages where sleep can become elusive.

Of course, you don't need a specific reason to appreciate it. If you've ever spent a summer night flipping your pillow over in search of the cool side or lying awake wondering whether you could buy another fan to keep you cool, you're exactly the kind of person Eight Sleep has in mind.

What is the Eight Sleep Pod 5 Cooling Mattress Topper like to use?

The Eight Sleep Pod 5 delivers a sleeping experience that's unlike anything we've tested before. During our trial period, much of the UK was sweltering through heatwaves. And yet, our tester, Sally, found she could sleep in her usual pyjamas "I almost forgot how hot it was outside," she told me. "Normally I'd be opening windows and throwing the duvet off, but with the Pod, I just slept like normal."

Sally tested the blanket with the Pod 5 and loved having the cooling effect comes not only from the mattress cover itself but also from Eight Sleep's temperature-regulating duvet, which works with the system to create a noticeably cooler sleep environment.

Whilst Sally was feeling pretty smug about sleeping through the heatwave, she noted that there was work needed before she reached her perfect slumber state. She noted that first few nights felt surprisingly strange, particularly if you've spent your whole life climbing into a warm or even room-temperature bed.

"Getting into a cold bed felt completely wrong at first," Sally admitted. "My instinct was that beds are supposed to be cosy and warm and the cold actually made me feel like the bed was wet, or just a little off. But after a few nights, my body became used to the feeling and it knew to expect a cooler experience."

Heatwaves aside, Sally was grateful for the cooling feature when she came down with a fever during testing. "I spent a day in bed feeling awful and turned the Pod right down to 17 degrees. It made such a difference. Usually when I have a temperature I feel trapped by the heat and just lie in bed with a frozen flannel on my face, but this helped me feel more comfortable and I could snatch some naps and sleep without waking up as a sweaty mess."

The duvet also took some getting used to for Sally. Because it's designed to work with the Pod system, it sits differently from a traditional duvet and feels more anchored to the bed. "It's almost like having the duvet permanently tucked in at the end," Sally explained. "You can't really wrap yourself up in it. I noticed it immediately because I'm someone who wraps the duvet around my shoulders. and between my legs" However, she found that once she'd adjusted to the setup, the benefits outweighed the change. "I slept much more deeply than I normally do, and I wasn't waking up because I was too hot."

One of Sally's favourite features was the app, which we'll talk more about later. As an overview, the app is where you fine-tune the bed temperature of your bed, and it's also where the Pod will let you know when it's made automatic overnight adjustments using its Autopilot mode.

"I liked knowing about the autopilot mode, working away in the background," Sally said. "I wasn't constantly fiddling with settings because the Pod 5 seemed to know when I needed cooling down. I think that's why I was waking up fewer times. The smaller hot flushes that I would have had were being minimised and the bigger ones, which still woke me up, felt more soothed and easy to control."

The smart alarm also won her over. Rather than jolting her awake with a loud noise, the Pod can vibrate the mattress or warm the bed to wake you gradually. "It feels much less aggressive than a phone alarm," Sally said. "Then you just press the button on the side of the bed to stop it."

For anyone worried about comfort, Sally reported that the technology quickly fades into the background. "You can't feel any of the tubes or water channels when you're lying down," she said. "If I hadn't known they were there, I wouldn't have guessed." The accompanying hub unit does make a faint sound while it works, but it proved unobtrusive during testing. "It's more of a soft background hum than a noise," she explained. "After the first night, I stopped noticing it altogether."

Does the Eight SLeep Pod 5 help with night sweats?

For women dealing with perimenopause, menopause, or simply running hot at night, the Eight Sleep Pod 5's biggest selling point is its ability to respond to temperature changes before they fully wake you up. Unlike cooling bedding, which can only passively disperse heat, the Pod actively cools the mattress surface throughout the night. Sally tested the Pod during some exceptionally warm weather and found the difference was noticeable almost immediately.

"I usually wake up feeling overheated at least once or twice a night," she told me. "With the Pod, I wasn't waking up as sweaty and uncomfortable. I'd occasionally become aware that I was getting warm, but before I fully woke up, the bed would feel cooler again. And on the times that I did wake up, it wasn't with the maddening levels of heat that I've become used to." If, like Sally, you experience hot flushes, there's also a dedicated Hot Flash Mode designed to recognise sudden temperature spikes and respond with additional cooling.

What impressed Sally most was that the cooling felt natural rather than artificial. "It's not like sleeping under an air conditioning unit or having a fan blasting at your face," she explained. "The whole bed just feels consistently cold and comfortable." While it won't cure the underlying cause of night sweats, it does address one of the biggest frustrations: waking up because you're too hot.

What health data does the Eight Sleep Pod 5 track?

The Eight Sleep Pod 5 is as much a sleep tracker as it is a cooling system. Every morning, the app provides a detailed breakdown of your night's sleep, including how long you spent asleep, how often you woke up, your sleep stages, heart rate, heart rate variability, and breathing rate. For data lovers, it's a fascinating window into what happens after your head hits the pillow.

Sally found herself checking the app every morning. "I became slightly obsessed with it," she laughed. "It was interesting to see how different habits affected my sleep score. If I'd had a late dinner or a glass of wine, I could often see the impact the next day." The app presents the information in a clear, user-friendly format, giving you a nightly sleep score alongside personalised recommendations designed to improve recovery and sleep quality.

Perhaps most useful is the way the data works alongside the Pod's temperature controls. Rather than simply telling you how you slept, the system uses those insights to inform future adjustments through Autopilot. "It feels like the bed is learning what works for you," Sally said. "The longer I used it, the less I thought about settings and the more it seemed to take care of itself." For anyone interested in understanding their sleep patterns, the Pod 5 offers far more insight than a standard fitness tracker, while simultaneously working to improve the conditions that help you sleep better in the first place.

How does the Eight Sleep Pod 5 Cooling Mattress Topper compare?

There's no escaping that the Eight Sleep Pod 5 is expensive. However, the experience is impressive and it is, undeniably, effective, but what else is out there? And are there alternatives to the Eight Sleep that are good too?

Should you buy the Eight Sleep Pod 5 Cooling Mattress Topper?

If you really, deeply care about your sleep, it's hard to beat the Eight Sleep Pod 5. It's a premium piece of kit that helps manage heatwaves, hormones, and bodily fluctuations using smart technology that actually works. It sold Sally, our tester, who enjoyed deeper, more comfortable sleep. However, it's worth factoring in the subscription cost and an adjustment period for this very different style of sleeping.

How we test mattress toppers

At woman&home, we have a series of standardised tests that we put all of our mattress toppers through. However, the Eight Sleep is a little different. Our focus for testing this wasn't just about comfort levels, we wanted to dig deep into the cooling power, the sleep tracking, smart features, and hormone help claims. We worked through all of these for months before writing up this review, so you're getting as much detail and real-life evidence as possible. However, we know this is a big purchase, so will happily answer any questions you have over email.

You can also read more about how we test mattress toppers on our dedicated page.