Does a cooling mattress help you sleep?

Does a cooling mattress help you sleep?

It depends on what is keeping you awake. If it is heat, a cooler bed goes at the cause; if it is a busy mind, it does not.

Even for heat, the evidence is thinner than you might expect. A 2025 systematic review pooled nine randomised trials of bedding designed to cool the body — mattresses, toppers and pillows — in healthy adults. Some lowered core body temperature in the short term, but together they showed no differences in how long people took to fall asleep, how long or how efficiently they slept, time in each sleep stage, or waking in the night, and the review rated the certainty of that evidence low to very low (Pasquier and colleagues, 2025).

Small, varied trials can miss a real effect, so this is not evidence that cooling beds do nothing. It is evidence that nobody has yet shown, reliably, what they do for sleep.

Why a cooler bed might help at all is in what happens when you fall asleep: the way into sleep runs downhill in temperature, with heat leaving through the hands and feet.

What does research say about bed temperature and sleep?

That the bed sits between you and the room, and shapes how easily you shed heat. A 2012 review of the research found that, with the bedding and clothing people actually use, heat increases wakefulness and reduces deep and REM sleep, and humid heat adds to the load. Cold, with bedding, left the sleep stages alone but changed how the heart was regulated during sleep — and the authors suggest that in real life, being too cold may matter more than being too hot (Okamoto-Mizuno and Mizuno, 2012).

So “cooler” is not automatically “better”. What seems to matter is a body that can lose heat comfortably, not a cold one.

A mattress can move heat by itself, too. In a double-blind 2020 study, 32 healthy men in their 40s slept on either a high-heat-capacity mattress, which draws warmth out of the body by contact, or a conventional one. On the first, core temperature fell further, heart rate slowed and they had more deep sleep (Herberger and colleagues, 2020). The study was funded by an Italian company, Technogel Italia.

What have studies of cooling mattress pads found?

Fewer than you might expect, and most are small. These are the studies of active, temperature-controlled covers and pads we could find in Europe PMC in October 2026:

Read together, they show a pattern. People like sleeping on these devices and rate their sleep better. Measured sleep moves less: in the one independent randomised study it did not change significantly, and the company’s own study found gains of 9 to 14 minutes in deep or REM sleep. The biggest effect came from a university prototype that cooled the middle of the bed while warming its edges and the neck — one night each way, in 11 young men. Of these studies, only one tried to hide from people whether the device was working — run by a maker, in 14 people, and not yet peer reviewed.

What is Eight Sleep, and what does it claim?

Eight Sleep is a New York company, and the Pod is its product. As its UK website described it on 14 October 2026, the current model, Pod 6, is a cover about 2.5 cm thick that fits over an existing mattress like a fitted sheet, linked to a unit called the Hub that sits beside or under the bed. It cools or heats each side of the bed separately, anywhere from 12 °C to 43 °C, tracks sleep and health through sensors in the cover, and adjusts the temperature through the night automatically, through a subscription the company calls Autopilot, which it says is required for the first 12 months. Add-ons include a base that raises the bed to reduce snoring, a water-fed blanket and a pillow cover (Eight Sleep).

Its science page, headed “Clinically-backed sleep fitness”, says that after sleeping on the Pod its members see more deep and REM sleep, a lower sleeping heart rate, better sleep quality and faster sleep onset. The one journal article it links to is the company’s own one-week study, the first row of the table above (Eight Sleep; Moyen and colleagues, 2024).

Sheeps has not tested the Pod, or any other cooling mattress.

Is Eight Sleep worth it?

We cannot answer that for you: it depends on what keeps you awake, and on what the money means to you. What the studies so far support is this:

• People tend to feel they sleep better on it. That is the most consistent finding, in both independent studies of the Pod (Stevenson and colleagues, 2025 and 2026).
• Measured sleep did not change in the one independent study that measured it. None of the Pod studies hid from participants whether it was switched on, so expectancy has not been ruled out.
• It has not been tried where it would matter most. We found no trial of the Pod in people with insomnia, and none longer than about three weeks (searched October 2026).

Who might notice a difference: people who wake because they are hot; couples who want different temperatures, since each side is set separately; women with menopausal night sweats, on the strength of one small pilot of a cooling pad; and anyone sleeping through hot weather without air conditioning. Who probably will not: anyone whose nights are long because of a busy mind rather than a warm bed — for that, racing thoughts at night is the better place to start.

The Pod also tracks your sleep, which some people find useful and others find a new thing to worry about: are sleep trackers accurate?

What are cheaper ways to a cooler bed?

A bed can be made cooler for much less:

• A cooler bedroom. The cheapest change of all; you have to cool down first gives a range to aim for.
• Lighter, more breathable bedding and nightclothes. Outside the laboratory, bedding and clothing decide how much a warm night costs you, and humid heat is harder on sleep than dry (Okamoto-Mizuno and Mizuno, 2012).
• A warm shower or bath 1 to 2 hours before bed. In a 2019 review of 17 studies, water at 40 to 42.5 °C for as little as 10 minutes, 1 to 2 hours before bedtime, went with falling asleep sooner, which the authors put down to the fall in core temperature that follows (Haghayegh and colleagues, 2019). A hot shower before bed has the details.
• Warm hands and feet in a cool room. They are not a contradiction: warm hands and feet are how the body lets heat out on the way into sleep (what happens when you fall asleep).

A bedtime routine for adults puts these together into an evening.

When is being hot at night worth seeing a doctor about?

When it is night sweats rather than a warm room. The NHS says it is normal to sweat at night if the room or your bedding is making you too hot, and describes night sweats as sweating so much that your nightclothes and bedding are soaking wet, even though where you sleep is cool.

It advises seeing a GP if night sweats happen regularly and wake you up or worry you, if they come with a very high temperature (or feeling hot, cold or shivery), a cough or diarrhoea, or if you are losing weight for no reason. The most common causes it lists are menopause symptoms, anxiety, some medicines, low blood sugar, alcohol or drug use, and a harmless condition that makes you sweat too much (NHS).

A cooling pad may make menopausal night sweats easier to sleep through. It cannot tell you why they are happening, and new or severe ones are worth a doctor’s view first.