Best cooling mattresses

Almost every cooling claim in this category describes a treatment: a gel infusion, a cool-touch cover, a phase change panel. All of those conduct heat away from your skin at the point of contact, which is real.

The heat then needs somewhere to go. In foam there is nowhere: small closed cells, almost no air movement, so it travels a few centimetres and stops. That is why treated foam feels cool for twenty minutes and then stops mattering.

In a mattress with open structure, heat reaching that structure can actually leave. So the question is never what the comfort layer is called. It is whether there is a spring layer and how deep it is.

The picks

Otty Original Hybrid Mattress: Best overall for heat

Around £500 · 8.1 / 10

Otty's whole argument is a 16 centimetre spring layer, which is a support core rather than a thin comfort layer of micro-springs. That is a large volume of open, continuous gaps that flex with every movement, and it moves a great deal of air.

Note the distinction, because it is where brands are compared wrongly: Otty's springs are 16cm tall and sit in the support core. Simba's Aerocoils are 25mm and sit in the comfort layer. They are not the same component doing the same job.

Read the full Otty Original Hybrid Mattress review

Purple: Coolest surface available

Premium · 7.4 / 10

The only 10 out of 10 for temperature on this site. The comfort layer is an open grid that is mostly empty space, so air moves through the part of the mattress touching you rather than around it. That is the most complete structural answer to heat available in Britain, and the feel divides people sharply.

Read the full Purple review

Origin LumbarCloud Mattress: Best deep spring option

£797 · 8.2 / 10

Thirty-five centimetres and up to 8,000 springs. A very deep spring layer is a large volume of open structure, and it moves a lot of air. It is also a specification hand-built British bedmakers charge two to three thousand for.

Read the full Origin LumbarCloud Mattress review

Simba Natural Hybrid Source Mattress: Best for clamminess rather than heat

£899 · 7.5 / 10

Natural fibres absorb moisture vapour into the fibre and release it as conditions change. That matters because the sensation people describe as sleeping hot is usually clamminess rather than temperature. Damp fabric against skin feels warm whatever the air temperature.

Read the full Simba Natural Hybrid Source Mattress review

Mlily Haluna Natural 4000: Best value natural

Mid range · 7.5 / 10

Natural fillings over 4,000 springs, which is the correct pairing: natural fibres settle into a plush surface, and a plush surface needs a high spring count so each region responds independently. At this price that combination is rare.

Read the full Mlily Haluna Natural 4000 review

Airflow, ranked by construction

The free check on any cooling claim: ask whether there is a spring layer and how deep it is. If the answer is a number in centimetres, the word means something. If the answer describes the cover, it does not.

And the distinction that matters within hybrids: gel over foam is a treatment. Gel over springs is a treatment on top of a mechanism. The gel helps heat reach the springs slightly faster; the springs are what remove it.

Two cheaper causes, and you should rule them out first

Most people who buy a cooling mattress did not need one.

Your duvet. A 13.5 tog duvet suited poorly insulated houses. Many modern homes never drop far enough at night to need one, and 7 to 10.5 tog is the useful range. If you wake up hot in January, this is the more likely cause and it costs a fraction as much.

Your mattress protector. Cheap waterproof protectors are essentially plastic sheets with a fabric face. They stop liquid and they also stop air. Put one over a deep spring layer and you have sealed off the airflow you paid for. This is the most common reason someone buys a hybrid for temperature and cannot understand why it sleeps warm.

Add a polyester pillowcase, which insulates while holding moisture against your face, and you have three fixes costing under a hundred pounds between them.

Heat or clamminess? They need different answers

Worth separating, because the materials differ.

If you are genuinely hot, you need airflow: open structure, a deep spring layer, a grid.

If you wake up damp, you need moisture management: wool, cotton, lyocell. Those absorb moisture vapour into the fibre and release it as conditions change, rather than holding it at the surface as polyester does.

Most people describe both as sleeping hot, and the second is more common than the first.

What not to buy for cooling

An all-foam mattress with a cooling treatment. Gel, graphite, copper, phase change: all of them conduct heat away from your skin and then have nowhere to put it. The effect fades within the hour and no amount of spending inside a foam range fixes it.

A memory foam topper on a hybrid. The worst pairing in bedding. It sits above the springs and cuts you off from the airflow that was the entire reason you bought the mattress. If you need a topper and sleep warm, buy wool, spacer mesh or micro-spring.

Ventilated foam, expecting a spring layer's airflow. Channels cut through foam are paths rather than pumps. Air moves through them when something drives it, and lying still, very little happens.

A cooling mattress before you have changed your duvet and your protector. Both are more often the cause and both cost a fraction as much.

How this list is made, and who made it

Who writes this. Kyle Klinkradt has worked in the mattress and bedding industry for over ten years across retail, distribution and brand partnerships, and has handled, sold or assessed products from every major UK bed-in-a-box brand. Every review on this site is written by one person, so the scores mean the same thing from page to page.

What the assessment is. Construction specifications against what they physically do: spring height and where in the mattress it sits, spring count for the size, gauge, whether the base is sprung or foam, foam density where it is published, comfort layer depth and material. Then the commercial terms that decide what you are actually buying: trial against returns policy, guarantee length against the company's UK trading history at Companies House, and the regulatory record.

What it is not. This is not a laboratory. I do not publish pressure-mapping data or claim to have slept eight years on every mattress here, because nobody has and pages that imply otherwise are not telling you the truth. Where a judgement rests on construction rather than long-term use, the review says so.

What gets a product removed. Leaving the UK market, a specification change that makes the review inaccurate, or a corrected fact. Brands that have withdrawn are kept on the site with the score removed rather than quietly deleted, because people still search for them.

See editorial independence, corrections and the author page.

How these were chosen

Every product here has its own review on this site with a score out of 10, and the score is a judgement rather than an average. Nothing appears in a list because it pays more.

A score is against the market, not against its own range. The cheapest mattress in a lineup is usually priced to make the model above it look reasonable, and the flagship of a budget range has risen into a bracket where better brands compete. Both are judged against what else you could buy for the money.

Everything listed can actually be bought in the UK. That is not a given: Casper withdrew in July 2020 and Leesa no longer sells here, and both still appear in current British roundups with affiliate links attached.

I do not pad the list. Where only three or four products genuinely qualify, there are three or four. A list of seven when the category contains four good ones is a list with three bad recommendations in it.

Prices move constantly. Judge the cash price on the day rather than any percentage beside it. See every review on this site or where the real savings are.

Questions people ask

What actually makes a mattress cool?

Open structure that lets air move through it. A deep pocket spring core or an open grid comfort layer does that; solid foam does not, treated or otherwise, because it has small closed cells and almost no air movement.

Do gel mattresses keep you cool?

At the point of contact, yes, and the heat then needs somewhere to go. In all-foam there is nowhere, so the effect fades within the hour. Gel over foam is a treatment; gel over springs is a treatment on top of a mechanism.

Why does my new hybrid mattress still sleep hot?

Most often a cheap waterproof mattress protector, which is effectively a plastic sheet that stops air as well as liquid and seals off the spring layer you paid for. After that, the duvet tog.

Is sleeping hot the same as clamminess?

Usually not, and they need different answers. Genuine heat needs airflow from open structure. Clamminess needs moisture management from wool, cotton or lyocell, and it is the more common of the two.