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What is the Best Temperature for Sleep?

Did you know that temperature can significantly impact the quality of your sleep? Most of us can relate to the feeling of being too hot and unable to drift off, but what is the best temperature for sleep? Let’s take a look at everything you need to know, and how you can achieve the optimum.

What’s the ideal sleeping temperature?

The best temperature for sleep is around 18.3 degrees Celsius1. This varies a few degrees person to person, but generally the ideal temperature for a comfortable sleep is 15.6 to 19.4 degrees Celsius.

How does temperature affect sleep?

Our bodies experience a dip in core temperature in the evening, coinciding with the sleep hormone melatonin. So, turning the heating off in the evenings or making the room cooler can help signal to your body that it’s time for bed. Keeping your bedroom cool can also help you maintain sleep throughout the night2.

Remember, it’s not all about getting to sleep; sleep quality and staying asleep is important too. Cooler rooms can help you settle in and remain asleep – but you won’t want your room too cold.

What does the science say?

Your body’s temperature regulation is closely linked to sleep, shifting during a 24-hour period; also known as a circadian rhythm. The circadian clock plays a physical, mental, and behavioral role in response to light and dark, regulating functions such as appetite and sleep3.

Your body begins to shed warmth around the time you go to bed, continuing to cool down until reaching its low point near daybreak, at around 5 a.m. If the temperature in your sleeping environment is too hot or cold, it may cause you to have disrupted sleep by affecting the drop in body temperature.

What happens when your room is too hot?

Warmer temperatures when trying to sleep can cause:

  • Discomfort
  • Restlessness
  • Fatigue
  • Decrease in restorative slow-wave sleep
  • Decreased sleep efficiency
  • Less time spent in REM sleep4

Sleeping in a cooler room also has potential health benefits, not just for those with insomnia. It promotes the burning of excess fat, regulates metabolism and the hormone system5.

What is the optimal sleeping temperature for infants?

Infants may need a slightly warmer room for sleeping (1-2 degrees higher), but parents should be aware that an overly hot temperature can increase the risk of sudden infant death syndrome6. Infants are more sensitive to temperature as their bodies are smaller and still developing. Monitor the temperature of their bedroom with a thermometer and avoid heavy bedding or multiple layers.

Elderly people may also benefit from a room that’s slightly warmer too.

How to make a room cooler

Wondering how to create the perfect temperature for sleep? It can be easier said than done to create a cool sleeping environment. Most of us don’t have air conditioning, and sometimes fans just don’t quite cut it. However, there are many tips and tricks you can try to boost comfort levels.

1. Block out light during the day

During the day, keep curtains or blinds closed to block the sun out. Lights and appliances can generate a lot of heat, so turn them off unless they’re needed7.

2. Open windows in the right rooms

It’s tempting to open all the windows you can in a bid to cool rooms down, however, this may not be the right approach. Consider what direction the sun is facing; if your windows are south-facing, it’s best to close the blinds and open the window to allow some air in. For north-facing windows, keep them shut to avoid any hot air coming in.

3. Create a cross-breeze

Position a fan across from a window, so the wind from outside combines with the fan. This should make a cooling cross-breeze. This can be done with multiple fans if it’s particularly hot8.

4. Change your bedding

Certain fabrics will make you feel hotter than necessary. Lighter, breathable sheets can help you avoid feeling sweaty at night and ensure the room doesn’t feel too stuffy. Go for pure cotton with a high thread count where possible.

5. Open the window

At night it can be a good idea to keep the window open to allow a breeze in while you sleep. Of course, this can be tricky if you live on a main road or in an area with a lot of noise.

6. Keep hands and feet cool

Try dangling your feet out of the duvet, and keep your hands out also, this can help your body stay cool if you find yourself heating up.

7. Have a bath before bed

Taking a hot bath 1-2 hours (ideally 90 minutes) before bed can help you fall asleep more quickly, by changing your body’s core temperature so that you go to bed with a lower temperature9. A drop in body temperature signals to the body that it’s time for bed.

How to get a good night's sleep

It’s not all about finding the perfect temperature for sleep. There are many different factors that play into how well you’ll sleep, how long it takes to drift off, and sleep duration. Try to manage stress levels, ensure your bed is comfortable and block out all light/noise. Relaxation techniques can help also.

Sleep is as important for your health as exercising and eating a healthy diet10, so it’s important you make it a priority. Lowering the temperature and keeping the room cool may help you sleep better if you’re struggling.

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