A hand gripping a rumpled white duvet on a warm night

Why Do I Sleep Hot Even With Cotton Sheets?

Cotton has a reputation as the breathable choice, so waking up warm on it can feel confusing. The fibre is only part of the story. How the sheet is woven, what happens to moisture overnight, and everything else on the bed all play a part.

Cotton breathes, but it holds on to moisture

Cotton is a good absorber. It soaks up moisture readily, which sounds helpful until you think about where that moisture goes. It stays in the fabric, next to your skin, and dries slowly.

Everyone loses some moisture through the skin at night. On a warm night, or if you tend to run hot, that adds up. A sheet that holds it close feels damp, and damp fabric against warm skin is a recipe for waking up, throwing the duvet off and struggling to settle again.

The weave matters as much as the fibre

Sateen versus percale

Two cotton sheets can sleep very differently depending on the weave. Sateen has a smooth, slightly glossy surface and a denser construction, which feels soft but holds warmth. Percale is a plain, crisp weave that tends to feel cooler. Many sheets sold as luxury cotton are sateen.

High thread count

A very high thread count often means thinner threads packed tightly together, sometimes doubled up. The result can be a denser fabric that lets less air through, not a better one. We explain why in why thread count is a myth.

Blends

Easy-care sheets are often polycotton. The polyester in the blend makes them cheaper and quicker to iron, but it traps heat and does little to move moisture away.

It may not be the sheets at all

Sheets are only one layer. If you have changed them and still wake up warm, look at the rest of the bed.

  • The duvet. A duvet that is too heavy for the season will overheat you whatever sits beneath it. Many people keep one duvet all year when a lighter one would suit the warmer months.
  • The mattress and topper. Dense foam can hold body heat, particularly if it is close to your skin through a thin sheet.
  • Nightwear. Synthetic pyjamas work against a breathable sheet.
  • The room. A warm, still bedroom makes everything harder. A cooler room and some air movement help.
  • The evening. Alcohol, a heavy late meal or exercise close to bedtime can all leave you warmer as you go to sleep.

When to speak to a GP. Night sweats that are persistent or drenching, or that come with other symptoms, are worth raising with your GP. Bedding can make nights more comfortable, but it is not a treatment.

What to look for instead

If cotton keeps leaving you warm, look for a fabric that moves moisture away rather than holding it, with a smooth, breathable weave and nothing synthetic blended in.

That is why we chose eucalyptus lyocell for The Sheets. It is a plant-based fibre made from eucalyptus pulp. The structure of the fibre carries heat away from the body and moves moisture away from the skin, so the surface you sleep on stays cooler and drier. That comes from the fibre itself, not from a cooling treatment, so it does not wash out. It is cool to the touch, and it gets softer with every wash.

The Sheets by Mossva

For nights that run warm

100% eucalyptus lyocell that carries heat away from the body and moves moisture away from the skin, from the fibre itself.

30-night guarantee. Feel the difference or we will refund you in full.

Shop The Sheets from £135

A few small changes that help tonight

  • Swap to a lighter duvet for the warmer months, or keep a lighter one for warm spells.
  • Choose loose, natural-fibre nightwear, or none.
  • Open a window or run a fan for air movement.
  • Skip fabric softener. It coats fibres and makes it harder for them to move moisture.
  • Keep a spare pillowcase nearby, so you can turn to a fresh one without changing the whole bed.

Common questions

Is cotton a bad choice for hot sleepers?

Not necessarily. A crisp percale cotton suits some people well. The issue is that cotton absorbs moisture and holds it, and many cotton sheets are woven densely, so if you run warm or sweat at night it may not be the coolest option.

Is linen cooler than cotton?

Linen is very breathable and many people find it cool. Its texture is substantial, which some love and others find rough against warm skin.

What is the coolest weave for sheets?

A plain, crisp weave such as percale tends to feel cooler than a dense sateen. The fibre matters too: one that moves moisture away from the skin keeps the surface drier through the night.

Why do I only overheat in the early hours?

Heat and moisture build up under the duvet through the night. By the early hours a sheet that holds moisture can feel damp and warm, which is often when people wake. If night sweats are frequent or drenching, speak to your GP.

How do I wash eucalyptus lyocell sheets?

Machine wash cold at 30 degrees, tumble dry low, and skip bleach and fabric softener.

Read next: cooling sheets for hot sleepers

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