Surviving the Heatwave: Tips for a Cooler Night’s Sleep

As temperatures soar, many of us struggle to fall asleep, stay asleep, and wake up feeling refreshed. But the secret to a good night’s sleep may begin hours before bedtime.

When temperatures rise, our body’s thermoregulation system is put to the test. Thermoregulation is the body’s ability to maintain its internal temperature within a safe range, and sleep is closely linked to body temperature. To fall asleep and stay asleep, the body usually needs to lose some heat.

Hot bedrooms make it harder for our body to lose heat, and UK summers are becoming hotter. The Met Office has reported that the chance of exceeding 40°C in the UK is now more than 20 times higher than it was in the 1960s, with a 50% chance of another 40°C day in the next 12 years.

Humidity can make the problem worse. Research on humidity and heat stress shows that high humidity can increase the strain heat places on the body. The body cools itself partly by sweating, but when the air is already humid, evaporation becomes less efficient.

Eight Essential Tricks to Beat the Heat

So, how can you sleep better in hot weather? Here are eight essential tricks to beat the heat and get a good night’s sleep:

1. Block Sunlight During the Day

On sunny days, keep curtains or blinds closed on sun-facing windows. This reduces sunlight entering the room and heating up floors, walls, and furniture. External shading, such as shutters, awnings, or shades, can be even more effective because it stops some sunlight before it reaches the glass.

Be careful with windows. If the air outside is hotter than the air inside, opening windows can bring heat in. Open windows when the outside air is cooler than indoors, often early in the morning, evening, or overnight. Close them during the hottest part of the day if the outside air is warmer.

2. Use Cross-Ventilation When the Air Outside is Cooler

Cross-ventilation means opening windows or doors on different sides of a home so air can flow through. When outdoor air is cooler, this can help remove heat that has built up indoors. Studies of passive cooling in homes have found that night-time ventilation can reduce overheating, although effectiveness depends on the building, outdoor temperature, safety, noise, and air quality.

3. Reduce Heat from Conservatories and Sun-Facing Rooms

Conservatories can become very hot because sunlight passes through the glass and warms the surfaces inside. Keep them ventilated during the day and, where possible, close internal doors between the conservatory and the rest of the house. Reflective films, blinds, shutters, awnings, and shaded roofs can all reduce heat gain.

Loft spaces and top-floor rooms can also become hot because roofs absorb solar heat. Loft ventilation or reflective roof materials may help in some homes, although these are usually more substantial interventions. For example, solar panels on the roof can generate electricity and at the same time act as a barrier to reduce heat transfer to the building.

4. Use Appliances Wisely

Ovens, hobs, tumble dryers, washing machines, and dishwashers can all make indoor spaces warmer. Cooking and drying clothes indoors can also increase humidity, making it harder for sweat to evaporate.

On very hot days, use heat-producing appliances earlier in the day or later in the evening. Use extractor fans when cooking or showering because they remove warm, moist air before it spreads through the home. Research on moisture movement and extractor fans has shown that fans can reduce the movement of moisture from kitchens and bathrooms to other rooms.

5. Choose Breathable Bedding and Clothing

A review of sleepwear and bedding fibre types found that bedding and clothing can affect thermal comfort during sleep. Light, loose sleepwear and bedding can help the body lose heat. Cotton and linen are often comfortable because they absorb moisture and allow air movement, although fabric weave, thickness, and moisture handling also matter.

Avoid heavy bedding, thick duvets, and tight synthetic fabrics that trap heat and moisture.

6. Use Fans Wisely

Electric fans can be useful in hot weather, but their safety depends on temperature, humidity, age, hydration, and health. Fans do not cool the air. They move air across the skin, which can help sweat evaporate and make people feel cooler.

However, in very high temperatures, especially for older adults or people who are dehydrated or unwell, fans alone may not be enough. If using a fan, drink water, avoid directing it continuously at the face while sleeping, and stop using it if it makes you feel hotter, dizzy, or unwell.

7. Use Cooling Devices

Reusable ice packs, freezer blocks, or cooling pillows may help some people feel more comfortable. Wrap ice packs in a cloth or place them on a tray to avoid condensation soaking bedding or direct cold contact with skin.

Cooling mattress toppers and bedding that use water or phase change materials may also help. These materials absorb, store, and release heat as they change state, although cost and effectiveness vary.

8. Combine Strategies for the Best Results

The most effective approach is usually a combination of these strategies: block sunlight during the day, ventilate when outside air is cooler, reduce heat from appliances, sleep in the coolest room available, and use bedding that allows the body to lose heat.