It's Not You. It's Not Your Partner.
It's Your Blanket.

You know the routine. You get into bed, pull the covers up, and for about twenty minutes it’s lovely. Then the heat starts to build. You’re too warm, a bit clammy, so you kick the blanket off. Now the room air hits you and you’re too cold, so you drag it back on. And you’re too hot again. Round and round, half the night.

If you share a bed, it’s worse. One of you is roasting while the other is shivering, both fighting the same blanket that only ever seems to have two settings: sweating or freezing.

It’s usually not you, and it’s not the room. It’s the blanket. Most blankets are synthetic, and synthetics trap heat instead of letting it move. A 100% muslin cotton blanket does the opposite, and that one change tends to end the whole cycle. Here are the five reasons why.

Woman lying awake in bed with visible sweat under white bedding, illustrating common reasons for waking up at night drenched in sweat.

Synthetic Blankets Trap Your Body Heat And Have Nowhere To Put It

Polyester and fleece are basically sealed. The fibres pack together and hold a pocket of warm, damp air right against your skin, with no way for the heat or the sweat to escape. That’s why a synthetic blanket feels so warm so fast, and it’s the exact same reason you’re overheating and clammy an hour later. The warmth has nowhere to go, so it builds up on you.