It feels natural to want a warm, cosy bedroom, especially in winter. But when it comes to actually sleeping, a cooler room nearly always wins, and the reason is built into how your body falls asleep.
The drop that triggers sleep
To fall asleep, your core body temperature has to drop slightly. It is one of the signals your body uses to begin the process. In a room that is too warm, that drop is harder to achieve, so you lie there feeling restless without quite knowing why.
This is also why a warm bath an hour before bed helps. It sounds backwards, but the bath sends blood to your skin, and as you cool down afterwards your core temperature falls, nudging you towards sleep.
Getting the room right
A bedroom somewhere around sixteen to eighteen degrees suits most people, cooler than you might keep the rest of the house.
- Turn the heating down or off in the bedroom at night
- Crack a window if it is safe and quiet enough
- Use breathable bedding rather than piling on heat
- Keep your feet warm with socks, which oddly helps the rest of you cool
The simple test
If you wake in the night feeling clammy or throw the covers off, your room is probably too warm. Err on the side of cool, with enough bedding to feel snug. A bedroom on the cold side of comfortable is one of the cheapest sleep upgrades there is, and it costs less to run than a warm one too.