How does temperature affect our sleep?

Our core body temperature has its own day-night cycle, which means our temperature rises and falls over each 24 hours. At night, our core temperature slightly lowers to signal it’s time for sleep. When the weather is hot and indoor temperatures remain high, it’s more important than ever for our bodies to be able to lose heat effectively. We do this through our skin, with heat being lost through radiation, conduction and perspiration. How effectively we lose heat will depend on our surroundings, with hot, humid conditions making the process more difficult.


Simple steps for keeping cool at night

In the bedroom

When temperatures are high, it can significantly influence the duration and quality of your sleep. However, by adopting a few small changes you can make your bedroom a more comfortable place:

  1. If your bedroom is exposed to direct sunlight during the day, close curtains and blinds. The ideal room temperature for sleep is 16-17 celcius, so keeping the room in shade can help keep temperatures down.
  2. Open windows when the air is cooler and the house is in shade – this will encourage air flow. Electric fans can help to circulate the air and, if located close to the bed, may promote the evaporation of sweat from the body which cools you down. If the noise of a fan disturbs you, consider running it an hour or so before bedtime. Avoid the use of fans if any member of the household is unwell with an airborne illness.
  3. A hot water bottle filled with ice cold water is a great way of cooling the bed sheets before you climb in. Your skin temperature is influenced by its environment, so if you’re hot and clammy, this may help you feel a little more comfortable.
  4. Use thin cotton sheets which help to absorb sweat away from the body.
  5. Wear lightweight night clothes made of cotton or linen.

Preparing for bed

A few simple modifications may help ensure your body is ready for sleep:

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  1. Stay hydrated but avoid too much fluid in the evenings. Water is the best drink for hydration, limit caffeine-containing drinks including cola after lunchtime and minimise alcohol because it disrupts the quality of your sleep.
  2. Exercise a few hours before you go to bed. The exercise will temporarily increase your core temperature allowing it to drop again in time to promote sleep.
  3. Stick as close as possible to your normal wake/sleep cycle, don’t be tempted to change your routine.
  4. A lukewarm shower before bed is better than a cold one – cold water will close pores and interfere with your ability to sweat and evaporate any excess heat away.
  5. Feet and hands are important thermo-regulators, so keeping these extremities cool in hot weather may help promote sleepiness. Chill bed socks or wrist bands in the fridge and pop them on as you prepare for bed.

What to do if sleep evades you

If you simply can’t sleep, then get up and do something calming – read a book, write, meditate or listen to some music.

Whatever you do, avoid using your smartphone or tablet. Ideally stop using these devices at least one hour before bed – this is because the blue light they emit disrupts the production of your natural sleep hormone melatonin.

*With temperatures reaching an all time high, it is recommended that you try to stay out of the heat and cool yourself down as much as you can. Try to be mindful of friends, family and neighbours who might be more vulnerable in these conditions and seek medical advice should you begin to feel unwell.

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How does heat affect your sleep? Comment below and let us know...

This article was updated on 7 July 2022.

A qualified nutritionist (MBANT), Kerry Torrens is a contributing author to a number of nutritional and cookery publications including BBC Good Food magazine. Kerry is a member of the The Royal Society of Medicine, Complementary and Natural Healthcare Council (CNHC), British Association for Applied Nutrition and Nutritional Therapy (BANT).


All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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