How to sleep well when it is hot

Why is it harder to sleep when it is hot?

Your body goes through a series of changes in preparation for sleep. When it gets dark, your body makes more melatonin. This is a sleep hormone that signals to your body when it’s time to sleep, increasing tiredness. At the same time your body temperature also decreases.

So, when it’s hotter than usual – the higher temperatures can interfere with the natural cooling of your body before sleep. This can make it harder for you to fall asleep and may cause you to wake up more often too.

Waking up in the earlier stages of sleep because it's too hot can reduce how long you spend in slow wave sleep. This is also called deep sleep. If you don’t get enough, you may not feel as refreshed the following day. But you can make changes to both your routine and sleeping environment to achieve quality rest.

How can I sleep better in the heat?

Aim to keep your bedroom temperature at around 18 degrees. Any higher than 25 degrees might disturb your sleep. It may be hard to keep this temperature during a heatwave. Here are tips you can try to sleep better.

Keep the curtains shut during the day

You might normally keep your curtains open during the day to let the light in. But on hot days this can make your bedroom hotter. Also, it’s better to wait until evening before opening the windows. The temperature outside should be lower than it is indoors by then.

Try lightweight, natural bedding

Try to find bedding made from natural cotton or linen fabrics. These can keep you cooler than bedding made from synthetic materials such as polyester. Bamboo materials work well too.

Freeze your pillowcases

Some people find popping their pillowcases in the freezer for an hour or so before bed can help. This can make you feel more relaxed when it's hot and may even lower your body temperature a little too.

Have a bath

Before bed, have a hot or lukewarm bath (not cold). Your body temperature will go down when you get out the bath, this will help you to sleep.

Don’t exercise before bed

Exercise in general is great for improving your sleep quality. But exercising close to bedtime can be disruptive, especially when it’s already hot. Exercising can raise your body temperature and make it harder for you to fall asleep at your regular time.

Is it healthy to sleep naked?

Wearing less clothing is ideal. Some people may like to sleep naked. But wearing lightweight cotton pyjamas might help you stay cool and fall asleep. This is because they form a barrier against your skin – so if you are sweating, you may feel more comfortable.

Other tips for sleeping well

• Maintain a good sleep wake routine. You might be tempted to change your routine to get up later or go to bed earlier when it’s hot. But keeping a regular sleep wake cycle can send signals to your body that it is time to rest. This makes it easier to fall asleep earlier in the night. Watch our video 'Busting sleep myths'.
• Reduce bright light exposure in the evening. Your body prepares for sleep when it gets darker outside. When you use bright lights inside, this can confuse your body’s signals and make it harder to sleep at an earlier time.
• Give technology a rest before bed. Social media and news sites can be stimulating before bed. The information and images you are exposed to via these platforms can promote wakefulness and make you feel anxious or stressed. This in turn can interfere with your sleep. Reading a paperback or using a kindle may be a gentler way to relax before bed.

If you regularly struggle with falling or staying asleep, or if you are concerned about your lack of sleep, then see a doctor. They can help you take control of your sleep quality again.