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Cooling Mattress for Hot Sleepers: What Helps and What the Evidence Says

bed.chat 2026-10-28

Being too hot at night can disturb sleep, making you toss and turn and wake up tired, according to CHOICE.

What "cooling" mattresses claim

CHOICE reports that cool mattresses appear across latex, foam and spring types, so buying based on construction alone will not guarantee a cooler sleep. Consumer Reports notes innerspring models generally retain less heat than foam because of the coils, but how hot a mattress feels ultimately depends on its overall construction. The same source adds that gel foam mattresses do not necessarily retain less heat than non-gel foams. CHOICE found more spring mattresses felt cool or very cool than polyurethane foam models in its tests, while its two latex mattresses also felt cooler but still collected a lot of sweat.

What independent testers say about heat

CHOICE says it now sees mattresses that actually deliver a cooler surface temperature, and it reports measured data rather than manufacturers' marketing claims. In its 2026 test, 13 of 18 mattresses recorded cool or very cool insulation, though CHOICE cautions many other mattresses aren't quite as cool as their makers think. CHOICE rates a mattress "cool" when its test shows the mattress moves body heat away from you efficiently. It also says mattresses scoring highly for breathability let lots of moisture through, so the surface is unlikely to get damp if it is humid or you sweat a lot.

Which? says highly breathable mattresses allow lots of moisture to pass through, so even on very humid summer nights or with night sweats the surface is unlikely to become damp. Which? also notes breathability is different from how warm a mattress feels to lie on, and it does not factor insulation into the test score because some people prefer warmer mattresses while others prefer cooler ones. Around 50% of the hybrids Which? has tested are rated "cold" or "very cold" to lie on, meaning they don't trap heat around you. For memory foam, Which? says some members find it too hot and suggests picking a model rated "cold" or "very cold" if you overheat in bed.

What the research says

A 2020 Sleep journal study (Herberger et al.) compared a high-heat-capacity mattress with a conventional low-heat-capacity mattress in a double-blinded fashion. The authors concluded the high-heat-capacity mattress subtly decreases core body temperature, leading to an increased amount of deep sleep stage N3 and a slowing of heart rate. A 2024 Scientific Reports study (Herberger et al.) included 72 individuals of varying age, sex and BMI using an identical high-heat-capacity mattress as a non-disturbing way of body cooling. It reported an increase in nocturnal deep sleep (N3) and a decrease in heart rate, while REM sleep did not change.

A 2025 Journal of Thermal Biology systematic review and meta-analysis screened 3,454 articles and included 9 randomized controlled trials of any bedding that induced body cooling in healthy adults. With very low to low certainty of evidence, the authors found no differences between cooling bedding and control bedding on sleep onset latency, sleep efficiency, sleep stage proportions (N1, N2, N3, REM), wake after sleep onset, or total sleep time. The included studies suggested bedding strategies lowered core body temperature in the short term, but the authors caution results should be interpreted carefully due to high heterogeneity in the estimated effects.

Ordinary low-cost things to try

The NHS Every Mind Matters guide notes noise, light, being too hot or cold, or an uncomfortable bed can make it harder to sleep. Before buying a new mattress, you can try lighter bedding, a fan or open window, and keeping the bedroom cool during the day. These are low-cost suggestions, not promises.

Checks before you buy

Look for measured test data rather than marketing claims — CHOICE says it reports actual data, not manufacturers' claims.
Check the trial period and return policy so you can test the mattress at home.
If you sweat heavily, consider that CHOICE warns foam mattresses may not last as long because sweat absorption can damage them over time and cause odours.
Run through the bed.chat checklist for firmness, certifications, foam density, size, frame and warranty, bed height for an older sleeper, trial and returns, UK online cancellation, warranty sag depth, and the "was" price.

For a personal answer matched to your sleep position, weight, budget, base and whether you sleep hot, try Bed Fit on the bed.chat home page. It asks nine quick questions and gives the mattress type, firmness range, size for your country and what to check before you pay.