It's July. It's 8 degrees outside. And you're lying in bed at midnight, one leg out from under the doona in the international symbol of the overheated sleeper, wondering what is wrong with you. Short answer: probably nothing. Long answer: one of these six things.
1. Your doona is doing too much
Most Australians own one winter-weight doona and use it year-round from April to October, regardless of whether their bedroom is 12 degrees or 22. If your room is heated, a high-warmth doona is overkill — you're sleeping under equipment rated for a Tasmanian cold snap.
2. Your sheets and pyjamas are synthetic
Polyester sheets, fleece pyjamas, and anything described as 'silky-feel' at a low price are usually plastic fibres — and plastic doesn't breathe. Heat and moisture get trapped in the microclimate between fabric and skin. Natural and plant-based fibres (cotton, linen, TENCEL™ Modal) let heat escape; our fabric comparison ranks them honestly.
3. Your body runs a nightly heat-dump
To fall asleep, your core temperature needs to drop about a degree, and it does that by pushing heat out through your skin — mostly hands and feet. If your bedding or sleepwear traps that heat, you feel it as 'running hot' right when you're trying to drift off. This is also why a warm shower before bed paradoxically cools you: it pulls blood to the skin and accelerates the dump.
4. The nightcap
Alcohol is a vasodilator — it flushes warm blood to your skin and disrupts the second half of your sleep for good measure. If you sleep hot, the evening wine is not your friend, sorry.
5. Late exercise
A hard session within a couple of hours of bed leaves your core temperature elevated exactly when it's meant to be falling. Train earlier, or accept the trade-off knowingly.
6. Hormones
For women, perimenopause can begin years before periods change — and disrupted temperature regulation at night is often one of the first signs. If overheating is new, persistent, and paired with the classic 3am wake-up, it's worth reading our night sweats guide and, if it's affecting your life, mentioning it to your GP.
The fix stack
Cooler room (around 20°C), lighter layered bedding, natural-fibre sheets, and breathable, moisture-wicking sleepwear. Work down the list in that order — or if you'd rather start with the layer that's actually touching you, the Lumen set was built for exactly this and comes with a 30-night trial.
General information only, not medical advice.
