How to Keep Your Bedroom Cool in a Heatwave

Keeping a bedroom cool during a UK heatwave is harder than it sounds — most British homes aren’t built with hot weather in mind. But with the right approach, you can usually bring bedroom temperatures down by several degrees.

Start early — block heat before it builds

The key principle is prevention. By the time your bedroom feels like a sauna, it’s already difficult to cool down. Start in the morning:

Close curtains on south and west-facing windows before the sun hits them. Light-coloured or thermal curtains work best — they reflect rather than absorb heat.
Close bedroom doors during the day to stop warm air circulating from the rest of the house.

Use windows strategically

The instinct to open all windows as soon as it gets warm is usually wrong during a heatwave.

Keep windows closed while it’s warmer outside than in. Opening them just brings in hot air.
Open them in the early morning and after sunset, when outside temperatures drop. A cross-breeze using windows on opposite sides of the house is ideal.
Ground floor windows and doors open at night can dramatically help airflow — if you’re comfortable doing so for security reasons.

Fans: how to use them properly

Fans don’t cool the air — they cool you by helping your skin evaporate sweat faster. Used well, they’re highly effective:

Position a fan to blow air across you, not just into the room generally.
For better cooling, place a bowl of ice or cold water in front of a fan. The air will pick up some moisture as it passes over.
Use a timer so your fan doesn’t run all night unnecessarily — or invest in one with a sleep mode.

See our best fans UK guide for recommended models.

What temperature should a bedroom be?

The NHS recommends keeping bedroom temperatures at 18–24°C for comfortable sleep. Above 24°C, most people find sleep significantly disrupted.

A cheap digital thermometer (around £5–8) is well worth having so you know what you’re actually dealing with.

Other bedroom cooling tips

Switch to lightweight cotton bedding — it breathes far better than polyester or synthetic blends.
Use a cooling pillow — designed to dissipate heat rather than trap it.
Freeze a hot water bottle and use it as a cool water bottle in bed (make sure it’s not dripping).
Take a cool shower before bed — this lowers your core temperature. It doesn’t need to be cold, just cool.
Avoid using the oven in the evening — heat from cooking takes a long time to dissipate.
Switch off electronics in the bedroom that aren’t being used. TVs, chargers and other devices all emit heat.

Also try: Blackout curtains are one of the most effective single investments for keeping a bedroom cool. They block both light and heat, and the difference in temperature can be significant.

Thermal mass: the longer-term solution

Rooms with more thermal mass — solid internal walls, stone floors — stay cooler naturally. This is why old stone farmhouses stay cool in summer. In a modern brick or timber-frame house, there’s less you can do about the structure, but keeping internal doors closed limits how much the house heats up as a whole.

When to seek help

If you cannot keep your bedroom below 24–26°C and you or someone in your household is elderly, very young, or has a health condition, take the situation seriously. The NHS has guidance on recognising and treating heat exhaustion — see nhs.uk.

Disclaimer: This article is for general information only. For medical advice about heat-related illness, consult the NHS website or your GP. For official heatwave warnings, visit the Met Office.