Sleep Science • Article

Why Do I Sweat When I Sleep?

Sleep Number

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It's normal to sweat while you sleep. But what's going on, exactly?


You go to bed shivering, only to wake up in a sweat. What's all that about? Assuming you're not down with a fever, sweating when you sleep is simply a matter of your body trying to regulate its own thermostat. We spoke with Sleep Number experts to explain what's going on.


Question: Is sweating when I sleep normal?

Answer: Yes, it is. Thermal regulation and sleep go hand-in-hand. And people are different. When it comes to how couples sleep, for example, one of the largest factors is sleep temperature, with 83 percent of couples reporting one or both partners sleep too hot or cold.*


Q: What causes sweating?

A: When you lie down, your body temperature drops. The faster it drops, the faster and deeper you sleep. Sweating occurs because your body is cooling off by releasing heat, and that heat is then trapped in the bed. Sweating when you sleep is a good thing, because it means your body is working the way it's supposed to.


Q: What can I do to avoid sweating?

A: If you don't enjoy waking up in a sweat, turn your thermostat down to about 65 to 67 degrees. Keeping your room at a cooler temperature helps signal the release of melatonin, which tells your brain that it’s time to go to bed. The data backs this up. Sleep Number® Smart Sleepers who say they “sleep cold,” tend to get the most restful sleep**. 


Use a fan to blow the heat away from yourself. Limit caffeine and food close to bedtime, as they speed up your metabolism which creates additional heat. Avoid strenuous activity before bed, which also raises the body temperature. A warm shower or foot bath before bed will also speed up the temperature drop. By letting the water evaporate off your skin, your body temperature will start to drop before you even get into bed. 


Discover how you can be sleeping at your Ideal Temperature with our True Temp™ bedding.


Q: Does it matter what I wear or what kind of mattress I use?

A. Yes. Fabrics such as synthetics and certain bedding materials such as various types of foam cause your body temperature to rise.

For a more comfortable night, try Sleep Number temperature balancing bedding, which pulls heat away from your body when too warm and releases heat as your body cools.


Like diet and exercise, quality sleep is essential for optimal wellbeing and performance. Because everyone's sleep needs are different, Sleep Number® smart beds sense your movements and automatically adjust firmness, comfort and support to keep you both sleeping comfortably. Find your Sleep Number® setting for your best possible night's sleep.


*Results from a 2020 Sleep Number survey of 1,004 respondents who reported they or their partner sometimes sleep too hot or too cold. 


**Based on SleepIQ® data from 1/2/20 to 1/1/21 and self-reported responses of sleepers using SleepIQ® technology from 5/12/19 – 1/1/21.

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