Latex vs memory foam if you sleep hot: which one, and why
If you sleep hot, the single biggest decision on a mattress is what the top five centimetres are made of. Memory foam and latex are the two you will be offered, and they behave in opposite ways with heat. Here is the difference, what each feels like, and how to combine them.
What each one is
Memory foam is a polyurethane foam made viscoelastic: it softens when it warms and flows slowly under pressure, so it moulds to you. It is dense and mostly closed-cell.
Latex is rubber foam, natural (from the rubber tree), synthetic, or a blend. It is made either by the Dunlop process (poured and baked, denser, firmer) or the Talalay process (vacuum, frozen, then baked, lighter and more consistent, and usually pin-cored with air channels). It is open-celled and springy.
What happens under you at 3 am
| Memory foam | Latex | |
|---|---|---|
| How it works | Needs your body heat to soften and mould | Springs back by itself; no heat needed |
| Air movement | Low: dense, closed cells | High: open cells, and pin holes in Talalay |
| Heat after an hour | Warm patch that follows you round the bed | Stays close to room temperature |
| Moisture | Holds it | Lets it through |
| Turning over | Slow: you climb out of the impression | Easy: it pushes back |
| Body impression over years | Yes, especially below 50 kg/m³ | Very little; latex is the longest-lasting comfort material |
| Feel | Sink-in, hugged, still | Buoyant, lifted, lively |
| Cost | Lower | Higher, especially natural Talalay |
For a hot sleeper the answer is latex on top, and it is not close. The things people love about memory foam, the hug and the stillness, are the same things that trap heat.
But I like the memory foam feel
Most people who switch find latex a relief after a week: easier to turn on, no warm hollow, no wrestling out of the impression to get up. If you genuinely want some sink, the trick is placement. A thin layer of memory foam under the latex gives a softer landing without the foam touching you. That is how our Hotel Bed is built: plush memory foam under natural fibres, so the sink is there and the heat is not.
What you should not do is put memory foam on top and rely on "gel", "open-cell" or a cooling cover to fix it. They help for the first half hour. See our guide on whether memory foam makes you hot for why.
Natural, synthetic or blended latex
- Natural Talalay or Dunlop: the most open and resilient, the priciest. Ask for the percentage; "natural latex" can mean 20 per cent.
- Blended: natural and synthetic mixed. Slightly less springy, noticeably cheaper, still cool.
- Synthetic (SBR): firmer and denser, closer to a regular foam in feel. Fine as a support layer, less good as the top.
For a hot sleeper, any of them beats memory foam on top; natural or blended Talalay is the best of them.
The rest of the bed matters too
Latex on top of a solid foam block still runs warmer than latex on top of springs, because springs have air between them. Look for a spring unit with a vented or mesh border. Then the cover: unquilted Tencel or cotton, not deep polyester quilting. Then a breathable protector, not a plastic-backed one. Then the sheets. Fix all four and the mattress is doing everything a mattress can.
How we built ours
The Hot Flush has no memory foam on top: 3 cm of pin-cored Talalay latex over 3 cm of graphite open-cell foam, over an egg-box layer that makes air channels, over 1,000 pocket springs with an open-mesh border, under an unquilted Tencel cover with a phase-change finish.
The short version
- Memory foam needs heat and holds it. Latex needs neither.
- Hot sleeper: latex on top, memory foam underneath if you want sink.
- Talalay over Dunlop for cooling; natural or blended over synthetic for feel.
- Springs, a vented border, a thin cover and a breathable protector finish the job.
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