How to sleep in a heatwave: a UK guide

British houses aren’t built for heat, so the first warm night of the year tends to catch everyone out. The good news is that most of what helps is free or close to it. Here’s a practical run through what actually works when you’re trying to sleep and the bedroom won’t cool down.

Cool the room during the day

The mistake most people make is throwing the windows open at the first sign of sun. On a hot day the air outside is warmer than the air inside, so you’re letting heat in. Keep windows shut and curtains or blinds closed on the sunny side of the house through the day, and you’ll start the evening from a cooler base. Then, once it’s genuinely cooler outside than in, usually late evening, open up and let the warm air out.

If you can create a draught by opening windows on opposite sides of the home, do it. Moving air carries heat out far faster than a single open window. There’s more on this in our guide to cooling a bedroom in a heatwave.

Move the air while you sleep

A fan doesn’t lower the temperature, but moving air helps sweat evaporate off your skin, and that’s what cools you. Point a tower fan across the bed rather than straight at your face, which dries you out less. An old trick that genuinely works: put a shallow tray of ice or a frozen water bottle in front of the fan so it pushes cooler air around. If a standing fan is too much, a neck fan can take the edge off.

The catch with fans is that above about 35°C they can blow hot air over you and stop helping much, so on the most extreme nights rely on them less and on a cooler room more. For bigger rooms or repeat heatwaves, a portable air conditioner is the step up, with running costs to match.

Sort out the bed itself

Swap a thick duvet for a sheet or a low-tog summer duvet, and pick cotton, linen or bamboo bedding over polyester, since natural fibres breathe and shift moisture better. If you sleep hot on a memory foam mattress, which traps heat, a cooling layer on top can help. We compare the options in our roundup of the best cooling mattress toppers, and explain what they can and can’t do in do cooling mattress toppers actually work.

A couple of cheap tricks help too. Put your pillowcase in a bag in the freezer for an hour before bed, and keep a glass of cold water on the bedside table. Some people swear by the “Egyptian method”, a lightly damp sheet over you, though it can leave the bed clammy, so it’s a try-it-and-see.

Prep your body before bed

A lukewarm or cool shower before bed brings your skin temperature down and rinses off sweat, both of which help you drop off. Keep the evening meal lighter, since digestion generates heat, and go easy on alcohol. A nightcap feels cooling but it disrupts sleep and dehydrates you, which makes a hot night worse. Drink water through the evening instead.

If you share a bed, sleeping apart for a few nights cuts the shared body heat. And if you have stairs, remember the coolest part of the house is usually downstairs, so the sofa or a floor mattress in the living room can be a sensible retreat on the worst nights.

FAQ

What’s the ideal bedroom temperature for sleep?

The Sleep Charity suggests around 16 to 18°C. You won’t hit that in a heatwave, but the closer you get the better you’ll sleep, which is why cooling the room during the day matters so much.

Should I sleep with a fan on all night?

For most people yes, it’s fine and it helps. Angle it across the bed rather than at your face to avoid drying out your eyes and throat. On nights above about 35°C a fan helps less, because it’s moving hot air.

Does a cold shower before bed help or wake you up?

A cool or lukewarm shower helps. It lowers your skin temperature and washes off sweat. A very cold shower can be a bit too stimulating right before bed, so aim for cool rather than icy.

Sources

Bedroom temperature guidance: The Sleep Charity, sleep environment.