Why Does My Body Heat Up When I Sleep?

A good night’s sleep is vital for our physical and mental health. After a good night’s sleep, we can complete our daily tasks properly. On the other hand, if you don’t sleep well, you’ll be feeling tired and sluggish the next day. This will make it difficult to concentrate and work or do chores. Therefore, it’s important to get 7-9 hours of high-quality sleep every night.

However, from time to time, every one of us experiences sleeping difficulties. One minute you’re snuggled up in your cozy bed, comfortably falling asleep, and the very next moment you start kicking off your blanket, sweating as if you’ve just ran a marathon. So, the real question is: how come we fall asleep so comfortably cozy and then wake up all sweaty?

There are many different causes of night sweats, so read on to find out what may be causing your sleeping difficulties. After tracking down the reason, you might just find a solution, too!

Why Is Body Temperature Important When You Sleep?

As you may know, every night, the human body produces a hormone known as melatonin. This hormone regulates night and day cycles or sleep-wake cycles. However, what you might not know is that the human body temperature begins to decrease as sleep time gets closer.

Everyday body temperature varies between 96.8 and 100.4 degrees Fahrenheit (36 and 38 degrees Celsius), and a normal circadian rhythm would have the body temperature begin to decrease from 8 p.m. until 5 a.m. Some research has shown that the optimal sleeping body temperature is around 60 and 68 degrees Fahrenheit (15.5 and 20 degrees Celsius), however, the rate of temperature shifts is also very important.

The sleeping process occurs when the core body temperature is decreasing at the fastest rate, meaning, when the body loses heat at a maximum velocity. These shifts in body temperature send signals to the human brain that it’s sleeping time. However, in some cases the body temperature doesn’t decrease at all. And if it doesn’t fall into the optimal range, it will be much harder for the individual to fall asleep.

Reasons You Get Hot While Sleeping

If you’re wondering how to control your body temperature, it’s best to understand what might prevent it from decreasing in the first place (in order to eliminate some of the reasons naturally). Here, we’ll give you some of the common reasons for extremely high body temperature during sleeping.

You Sleep With Another Person

If you’re sleeping with another person, the combined body temperature can increase the temperature under the covers, and even the temperature in the room. This applies to sleeping with pets, as well.

The human body is constantly emitting heat because our metabolism keeps working. This means that more bodies in a smaller space lead to a faster increase of the temperature in that area. The average body temperature is around 98.6 degrees Fahrenheit (37 degrees Celsius), therefore, if the room temperature is higher than this temperature, the body is going to absorb the heat from the room.

So, in order to get better sleep, and at the same time to continue sleeping with someone else, try to lower the temperature in your sleep environment.

You Sleep on a Memory Foam Mattress

Certain types of mattresses can make the body’s thermoregulation less efficient than others because they might trap heat between the mattress and the body. Mattresses that are made from memory foam, for instance, may cause you to feel higher body temperature during your sleep. If you sleep on a memory foam mattress, your body temperature is transferred to the memory foam so that it can warm up and mold to your body’s shape. Although this may make the mattress more comfortable, the heat that gets transferred back into your body may cause overheating.

However, there is a solution for this, because some mattress companies have added a topper over foam mattresses that’s made of wool. This top layer acts like a thermoregulator for the body, decreasing the chances that you’ll suffer from night sweats and hot flashes.

Room Temperature

Some studies suggest that the optimal temperature of the room where you sleep should be somewhere between 60 and 67 degrees Fahrenheit (15.5 and 19.4 degrees Celsius). This is because  the body regulates its own core temperature as we sleep, by keeping the body temperature low during sleep and then slowly increasing it as a signal that it’s time to wake up. By setting your thermostat at a lower temperature, you’re helping your body’s temperature regulation. On the other hand, if your room temperature is too high, it can obstruct the process and result in overheating (and low quality of sleep). So, the solution is to keep the thermostat at a lower temperature or crack a window open for better sleep.

Medications and Medical conditions

Certain medications have side effects that may provoke an increase in body temperature, especially at night. Here are some of them:

  • prescribed antidepressants or other medications for psychiatric conditions;
  • medications for diabetes and high blood sugar;
  • diuretics;
  • medications that are used in hormone therapy;
  • steroids;
  • and some recreational drugs, like cocaine or ecstasy.

Some medical conditions may disrupt the hormone balance that regulates the metabolism and other processes in the human body. This can result in unwanted symptoms like night sweats or increased temperature sensitivity. Thyroid disease (hyperthyroidism or hypothyroidism), some types of cancer, chronic stress, obstructive sleep apnea, and coronary heart disease are some of the medical conditions that can increase your body temperature at night.

Certain infections, such as the flu, pneumonia, colds, and tuberculosis, can cause night sweats due to the fact that the most common symptom of these infections is a fever.

Hormone Level Fluctuations

The fluctuations of human hormones, especially female hormones, can result in hot flashes and night sweats.

During premenstrual syndrome (PMS), night sweats are very common because of the fluctuations in the levels of progesterone and estrogen in a woman’s body. Additionally, when women are in perimenopause or menopause, they may experience hot flashes and night sweats due to the decreased level of estrogen and other hormones. Lastly, pregnancy is another stage where hormone fluctuations may lead to an increase in body temperature.

You can decrease overheating problems if you sleep with less covers or use bed sheets that are cooler to the touch and more breathable. For instance, you may purchase bed sheets that are made from bamboo or cotton.

Tips for Cooler Sleeping

Here are some tricks that you can try before you go to sleep in order to sleep better and avoid overheating:

  • Avoid alcohol before you go to bad;
  • Drink a hot beverage, such as milk with honey or a cup of chamomile tea;
  • Practice some relaxation techniques, such as meditation, deep breathing exercises, or bedtime yoga several minutes before you go to bed;
  • Always keep a cold glass of water by your bed at night to stay hydrated;
  • Take a hot shower an hour before you go to bed.

Concluding Thoughts

There are many potential reasons as to why your body heats up while you’re trying to sleep. Before you try to fix the problem, it’s important to identify the cause. Here, we explained some of the things that could have an impact on your good night’s sleep. Hopefully, you’ll be able to fix your sleeping difficulties naturally by changing your mattress, sleeping clothes and bedding, decreasing the temperature in your bedroom, or taking a hot bath. However, if your body temperature continues to rise while you sleep, the cause may be a medical condition and you should pay a visit to your doctor.