Last updated: August 2026
Cooling claims are everywhere: ice silk, arctic covers, cooling gel, temperature-regulating foam. Yet people still wake up sweaty at 2 am, because a cold-touch cover feels nice for ten minutes and then the mattress underneath takes over. Cooling is a system, not a feature, and this guide explains which parts of the system actually work.
Quick answer: The best cooling mattress in the UK is a hybrid with open-cell memory foam over pocket springs, because the foam lets air pass through it and the spring core is mostly air, so heat moves away from your body instead of building up underneath you. Cold-touch covers and gel layers help for minutes; airflow, moisture handling and support that keeps you on top of the mattress work all night. The REM-Fit 5000 Lux Elite is built exactly this way, with the deepest open-cell layer and highest spring count in the range, and is Good Housekeeping Approved 2026.
Why do you overheat at night?
You overheat at night when your body cannot shed the heat it produces, and three things stop it: humid air, foam that holds warmth against you, and bedding that traps both. The mattress is usually only one of the three.
Humidity is the sneaky one. When the air is humid, sweat does not evaporate properly, so your body cannot cool itself and you feel hotter even in a room that is not especially warm; if you wake damp rather than just warm, that is humidity. The Sleep Foundation puts the ideal bedroom at around 18°C, and our guide on how to sleep in a heatwave covers getting the room there.
Foam is the second culprit. The deeper you sink, the more foam wraps around you and the more heat it holds, which is why a plush, deep-contouring mattress often feels hot. The third is bedding: a thick synthetic duvet or a waterproof protector that does not breathe can undo half the cooling performance of a good mattress.
What is open-cell memory foam and why does it sleep cooler?
Open-cell memory foam is memory foam manufactured with an open cell structure, so air can pass through the foam instead of being sealed inside it. Traditional memory foam has closed cells that trap air and body heat, which is where its reputation for sleeping hot comes from.
The difference is in the material itself, not the cover. With open cells, the heat and moisture your body gives off can move through the layer and away from you all night, while the foam still softens against your hips and shoulders for pressure relief. A cold-touch cover works on the surface for the first few minutes; open-cell foam works through the whole comfort layer for the whole night.
Every REM-Fit hybrid uses open-cell memory foam as its comfort layer, and in REM-Fit's own customer data 84% of mattress shoppers say temperature regulation matters to them, which is why the range is built this way rather than relying on a cover.
How do pocket springs help a mattress sleep cool?
Pocket springs help a mattress sleep cool because a spring core is mostly air. Every time you move, air is pushed through the gaps between the springs, so the heat that passes down through the foam has somewhere to go.
Tall pocket springs that run the full depth of the mattress do this better than a thin layer of mini springs sitting in foam, and a second layer of springs adds more air space again. Support matters too: springs that hold you on top of the mattress rather than letting you sink into it stop a heat pocket forming around your body, and zoned springs that keep your spine level mean less tossing and turning, which is itself a source of heat.
Reinforced edges help couples in particular, because you can use the full width of the bed and sleep further apart on a warm night. Our memory foam vs hybrid comparison goes through the heat difference between all-foam and sprung builds in detail.
What should a cooling mattress have?
A cooling mattress needs to do four things: move heat away from your body, allow airflow through the build, handle moisture, and keep you supported so you do not sink into a heat pocket. Use this table to compare any mattress on those four before you look at the cover.
| What to check | What actually works | What is mostly marketing |
|---|---|---|
| Comfort foam | Open-cell memory foam that air can pass through | Closed-cell foam with gel beads or graphite added on top |
| Support core | Tall pocket springs running the full depth, ideally in two layers | Solid foam base, or a thin layer of mini springs sitting in foam |
| Cover | Breathable, moisture-wicking fabric | "Cold-touch" fabric on its own; it stops working within minutes |
| Support | Zoned springs that keep you on top of the mattress | Deep sink that wraps foam around you |
| Edges | Reinforced or encapsulated edges so couples can spread out | Soft edges that push you towards the middle |
| Protector and bedding | Wicking protector, cotton or bamboo sheets, a light duvet | Non-breathable waterproof protector, thick synthetic duvet |
If a mattress only talks about its cover and says nothing about airflow, moisture or the spring core, be careful. Our guide to mattress cooling technologies goes deeper on each one.
Which REM-Fit mattress is best for hot sleepers?
The REM-Fit 5000 Lux Elite is the best REM-Fit mattress for hot sleepers, because it has the deepest open-cell memory foam layer and the highest spring count in the range, 5000 tall premium pocket springs in two layers. More springs mean more space for air to move through the mattress, which is what gives the 5000 its edge on temperature regulation and why Good Housekeeping's reviewers singled out its cooling.
It is medium-firm at 7.5 out of 10, 25 cm deep, multi-zoned so the shoulders sink a little further than the hips, with encapsulated edges and partner motion isolation, and it is Good Housekeeping Approved for 2026. It suits couples, hot sleepers and anyone who wants a premium feel without sinking into foam.
REM-Fit 5000 Lux Elite Hybrid Mattress
Deep open-cell memory foam over 5000 tall premium pocket springs: the pressure relief of memory foam without the heat.
Shop the 5000 Lux Elite✓ 100-night trial (200 with a protector)✓ 15-year guarantee✓ Free UK delivery✓ 0% finance
Every model in our hybrid mattress collection shares the same open-cell foam and tall pocket spring construction, so the choice between them is feel rather than cooling. The 600 Lux Black Edition is a medium-firm 7.5 on 4000 dual-layer springs, made in the UK; the 4000 Ortho Elite is the firm 9 out of 10 for back pain; and the 3000 Supreme is the medium 6 out of 10 for side sleepers. Our hybrid vs ortho vs elite guide explains the differences.
Why do couples overheat more?
Couples overheat more because two bodies produce twice the heat and moisture in a bed with less free surface per person, and every movement one partner makes disturbs the other. It is why so many people say they sleep fine alone but overheat together.
A cooling mattress for a couple needs the airflow above, plus motion isolation so one partner turning does not wake the other, and reinforced edges so both can spread out on a warm night. Our best mattress for couples guide covers the rest. If allergies are part of the picture, a warm, humid bed makes symptoms worse too, and our allergies and asthma guide pairs with this one.
Does the rest of the bed matter?
Yes, and it is the most common mistake: buying a cooling mattress and then wrapping it in a non-breathable protector and a heavy synthetic duvet. The protector, pillow and sheets sit closer to your skin than the mattress does.
Use a protector that wicks moisture rather than one that just blocks it. The REM-Fit Tencel Cool Mattress Protector, Good Housekeeping's Best Cooling Protector for 2026, uses Tencel fibres to move sweat away from the body over a waterproof membrane, and it is silent where many waterproof protectors rustle.
REM-Fit Tencel Cool Mattress Protector
Wicking, waterproof and silent: the protector that lets a cooling mattress breathe.
Shop the Tencel Cool ProtectorYour head is one of the body's main heat-release points, so the pillow matters almost as much. The Snow Pillow uses a Nordic chill fabric with Tencel fibres that dissipates heat up to 10 times faster than cotton, and the 500 Cool Gel Pillow, a Good Housekeeping Winner 2026, pairs a cooling gel layer with memory foam support. Finish with cotton or bamboo sheets and a light duvet, or just a sheet in summer.
Cooling mattress myths
A cooling cover solves night sweats. No: covers help for minutes, and lasting cooling needs airflow, moisture handling and support.
Cooling gel means a cooling mattress. No: gel in closed-cell foam still traps heat once it has warmed to body temperature.
If you overheat, it is always the mattress. No: bedding and protectors cause more overheating than the bed itself.
Memory foam is always hotter than a hybrid. Mostly, but a hybrid you sink deep into can trap heat too, which is why support is part of cooling.
Best cooling mattress FAQs
Last updated: August 2026
Do cooling mattresses work for night sweats?
Yes, when the cooling comes from the build. Open-cell foam and a pocket spring core reduce heat retention and let sweat evaporate, which helps with night sweats; a cold-touch cover on a closed-cell foam mattress does not. Pair it with a wicking protector and breathable bedding, and check the room is not humid.
Is a hybrid mattress cooler than memory foam?
Usually, yes. A hybrid's spring core is mostly air and keeps you on top of the mattress, while all-foam beds contour deeply and hold heat. The exception is a hybrid with closed-cell foam on top and deep sink, which can still run warm.
What is the coolest type of mattress to sleep on?
A hybrid with open-cell memory foam over tall pocket springs. The open cells let air pass through the comfort layer, the springs let it escape through the core, and zoned support stops a heat pocket forming around your body.
Do gel memory foam mattresses keep you cool?
Only briefly. Gel absorbs heat until it reaches body temperature, usually within the first hour, and then holds it like any other closed-cell foam. Foam that air can move through keeps working all night.
What bedding makes overheating worse?
Thick synthetic duvets, non-breathable waterproof protectors and sheets that do not wick moisture. A waterproof protector that does not breathe is one of the biggest causes of "hot mattress" complaints, even on a mattress designed to sleep cool.
What is the best temperature for sleep?
Around 18°C, according to the Sleep Foundation, with most people sleeping well between 16 and 19°C. Close curtains by day, open windows at night once the outside air is cooler than the room, and use a fan to keep air moving.
Sources: Sleep Foundation, Best Temperature for Sleep; REM-Fit product specifications and customer data, August 2026.
