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5 cooling mattresses for hot sleepers: hand-picked by our mattress expert
A veteran consumer advocate with over two decades of rigorous product-testing experience, Lisa has led our mattress category since 2020 and joined our home energy team in 2024. Her mission is to bring transparency to the mattress deals market while delivering clear, actionable advice on home energy solutions.
Our mattress expert reveals five of the coolest and most breathable mattresses we've seen in the Which? test lab.
If you can’t stretch to a new mattress at the moment, or have just bought one, don’t sweat – we’ve also got top tips to help you stay cool at night.
Visit our best mattresses guide for in-depth advice on choosing the mattress type for you – plus our top-scoring mattress picks.
What makes a mattress 'cooling'?
There are two factors that make all the difference to how hot your mattress feels, and we test both thoroughly.
- Mattress insulation – How much heat the layers of a mattress trap around you, and how much is let through the layers.
- Mattress breathability – How effective the mattress cover and layers are at wicking away moisture.
We use specially designed humidity chambers to measure how much moisture can pass through the layers of each mattress we test. Highly breathable mattresses allow lots of moisture to pass through, so even on very humid summer nights, or if you suffer with hot flushes or night sweats, the surface of the mattress is unlikely to become damp as the moisture passes through the mattress layers.
The Sealy Ultra Elevate Lunar hybrid mattress, exclusive to DFS, is the most breathable mattress we've tested*. But only just! Our test data shows that the Simba Earth Escape is also very breathable.
These mattresses are both pretty pricey: you won't get much change from £2,000 if you buy the Sealy double mattress, while the Simba Earth Escape is around £1,600 full price for a double.
Luckily, you don't need to spend that much. The breathable options we've listed here are all cheaper than the average price of the mattresses we've tested, which is currently around £763.
To find out how durable and supportive these mattresses are, and whether they are Which? Best Buys, you'll need to read our mattress reviews.
Not yet a member? Join Which? for instant access to all our in-depth reviews.
5 cooling mattresses from Which? tests
Of the 273 mattress reviews currently live on Which.co.uk, we rate 169 as 'cold' or 'very cold' to lie on, so there's plenty of choice.
1. MattressNextDay Coolflex Ortho Luxe Pocket mattress
- Double
- Pocket sprung
- Very cold
Available from online retailer MattressNextDay, the Coolflex Ortho Luxe is a great choice for letting heat escape.
It's a double pocket sprung mattress that's breathable, feels very cold to lie on and isn't too bouncy.
We found that you won't sink into the layers of foam on top – an asset if that's something you don't like the feeling of.
It's worth knowing the cover isn't removable for washing.
Will this double mattress provide long-lasting support for your spine? Check before you buy – read our Coolflex Ortho Luxe Pocket mattress review.
2. Catherine Lansfield Lush Pocket 1000
- Double
- Pocket sprung
- Very cold
The Catherine Lansfield Lush Pocket 1000 double mattress combines a 15.5cm pocket-sprung core topped with several different layers of fibres and a non-washable cover.
Our tests revealed this mattress won't trap heat around you. In the most recent batch of mattresses we tested, it let the most heat through the layers, so it's defnitely earned its 'very cold' rating.
It's also breathable, so even if you tend to sweat at night it shouldn't make that worse, which is a relief, as the cover isn't removable for washing.
See our full Catherine Lansfield Lush Pocket 1000 mattress review to see if it's supportive enough for your favourite sleeping position.
Go to our mattress brands guide to discover the brands that came top of our exclusive customer survey – and the brands you should avoid.
3. Jay-Be Flex 1200 pocket sprung
- Double
- Pocket sprung
- Very cold
The Jay-Be Flex 1200 double mattress is a firm mattress made from a combination of pocket springs and several fabric layers.
Its large, 18.5cm pocket sprung core is topped with numerous layers of manmade fabric including e-Fibre made from recycled plastic materials, and was rated 'very cold' in our insulation tests.
It's also breathable and does a decent job of wicking away moisture, so it won't trap heat and make you overheat in bed.
Will it give you a comfortable night’s sleep and can it stand the test of time, though?
Read the full Jay-Be Flex 1200 pocket sprung to find out.
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4. Jay-Be Ryze Deep Quilted
- Double
- Open coil spring
- Very cold
This is one of the cheapest double mattresses we've tested recently. The open coil structure may be really bouncy, but it's great at letting heat through the layers, so the mattress does an excellent job of not trapping heat.
It also lets moisture through its layers so you won't end up a sweaty mess.
Its construction is really simple: layers of polyester on top of a 14cm core made up of open coil Bonnell springs. Jay-Be says it features layers of the brand's e-Fibre, which is made from recycled plastics.
Is it a good choice for side sleepers? Read our full Jay-Be Ryze Deep Quilted mattress review to find out before you buy.
5. Argos Home Elmdon Memory Foam
- Double
- Open coil spring
- Cold
Buy the Argos Home Elmdon Memory foam double mattress for £210 from Argos.
Don't be fooled by 'memory foam' in its name, this Argos Home double mattress is made with an open coil sprung core which does a great job of letting heat through – even with the foam top.
It not only earns a 'very cold' rating from our test labs, it also doesn't do a bad job of being breathable.
It is super bouncy though, which can be the downside of any open coil structure.
Read our full Argos Elmdon Memory Foam double mattress review to see if it's great at supporting you while you sleep.
Tips for sleeping in hot weather
- Make sure your bedding is made from breathable materials such as cotton. Need a new duvet? Find out which brands make the best duvets and check out the best pillows.
- Keep curtains and blinds closed during the day, but open windows (if it’s safe to do so) to create a through breeze.
- Take a cool or lukewarm shower in the evening to help cool you down before bed.
- Before you go to sleep, use a fan. Electrical Safety First advice says you shouldn't leave a fan on all night, though. Find out how to buy the best fans to help keep you cool.
- If you have the budget, consider investing in a portable air conditioner.
Looking to buy a new mattress? See our guide to the best mattress deals – it's updated every month with the best deals around.
* Based on all mattresses tested to our latest test programme up to June 2026, that are still available to buy.
Always check any sleep trial or guarantee T&Cs before buying.
