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, you start producing more melatonin – this is a sleep hormone that makes you feel relaxed and tired. At the same time your core 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 your deepest phase of sleep and if you don’t get enough of it, you may not feel as refreshed the following day. But it's possible to make some changes to your both your routine and sleeping environment to help yourself get more quality rest.
How can I sleep better in the heat?
Aim to keep your bedroom temperature at around 18 degrees. This is thought to be an ideal temperature for sleeping – any hotter than this and you might struggle to sleep well. It might not always be possible to maintain this temperature during a heatwave, but the following tips may help you to sleep better anyway.
Keep the curtains shut during the day
Whilst you might normally keep your curtains open during the day to let the light in – on very hot days this can make your bedroom hotter. Also, it is better to wait until evening before opening the windows – as 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. You could also try switching a duvet for a thin sheet.
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.
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 is already hot. This is because exercising can increase your core temperature and make it harder for you to fall asleep at your regular time.
What should I wear to bed when it’s hot?
You might think that sleeping naked may help you to stay cool and sleep better when it is hot outside. But some people may find it easier to remain cool and fall asleep if they wear lightweight cotton pyjamas. 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 is 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.
- 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.