Worried about high body temperature while sleeping?

Struggle with high body temperature at night? Here we look at body temperature control and some of the reasons why you might overheat in bed.
 

First the science: a bit about body temperature and sleep

Did you know? Temperature fluctuations at night are completely normal. In fact, it’s part of your body’s circadian rhythm or internal clock, helping to control your sleep/wake cycle. Thanks to various hormones, your body’s core temperature drops in the evening ready for sleep. This helps you to nod off. It then rises again in the morning preparing you to wake up. Some people can be particularly sensitive to this change leading them to wake up feeling too hot during the early hours.
 

How does body temperature regulation work?

Your body temperature regulator is called the hypothalamus. It is located at the base of your brain and works like a thermostat, responding to internal and external factors to keep your body within a degree or two of 98.6°F. The hypothalamus releases chemicals and hormones and works with other parts responsible for body temperature regulation such as your skin, sweat glands and blood vessels. Together they allow your body to warm up or cool down as needed to maintain a constant healthy temperature. The main two ways your body does this are shivering and sweating.
 

Common issues with body temperature regulation

Sometimes, the hypothalamus struggles with regulating body temperature. This can lead you to warm up and even overheat. When this happens at night it can be particularly unpleasant, leading to broken sleep and even uncomfortable night sweats. There are a number of reasons this might happen.
 
 

Reasons you might experience extreme body heat when sleeping

Here are some of the reasons you might find you struggle with extremely high body temperature while sleeping:

• Female hormones have a lot to answer for. As a woman, you’ll notice that in the days leading up to your period, your temperature rises slightly. While it might not be much, this can affect sleep and leave you feeling hotter than normal under the covers.
• At a more extreme level, when you reach perimenopause and menopause you may find that erratic estrogen hormones lead to blood rushing to blood vessels under the surface of your skin. This will cause your skin to flush and can result in hot flashes at any time of the day or night. Many women find that these are more disruptive at night.
• Pregnancy can cause you to struggle with body temperature regulation, again because of the high levels of estrogen circulating.
• A cold or fever may lead to high body temperature at night as your body fights to rid itself of infection.
• Certain drugs, such as prescribed antidepressants and other psychiatric medications, can lead to high temperatures at night.
• Certain medical conditions such as thyroid disease and some cancers can disrupt the number of hormones that are released into your body to regulate metabolism and other processes. This can lead to unwanted symptoms such as sweating or an increased sensitivity to temperature. This can be worse at night as your body’s temperature naturally rises in the early hours.

Other factors that can affect high body temperature at night

Your sleep environment can also affect your body temperature, causing you to wake if you become too warm or too cold. Here are some things to consider if you’re consistently waking with a high body temperature at night:

• Room temperature – a dip in temperature is useful to help your body ready itself for sleep. That’s why a cool room can be beneficial. Keep layers on hand though, so that if you awake feeling chilly later in the night you can pull another blanket over yourself.
• Mattress temperature regulation - some types of mattress can make body temperature control more difficult than others by trapping warm air between your body and the mattress itself. Memory foam in particular could cause you to experience high body temperature while sleeping. Heat from your body is transferred into the foam to help it warm and mold to the shape of your body. While this may make the mattress supportive, this heat is reflected onto your body and can lead to overheating. Adding a wool mattress topper may help if you suffer from extreme body heat when sleeping on a memory foam mattress.
• Choice of comforters and bedding – Non-breathable bedding such as polyester could exacerbate any problems of high body temperature while sleeping, as your body heat will be trapped inside the covers with nowhere to escape to. Instead opt for breathable wool bedding that will help your body temperature regulation and reduce the likelihood of night time awakenings through being too hot. By choosing bedding that helps keep you cool when you’re warm and warm when you’re cool, you’ll be much less affected by spiking temperatures overnight.

If you experience extreme body heat while sleeping, try creating a more cooling sleep environment by using some of the tips above. But if you continue to struggle, or you can’t pinpoint the cause, you should discuss your concerns with your physician.

Find more ideas to help you sleep better at night when you visit our Sleep Health & Advice hub.