Why Does My Body Temperature Go Up at Night? - And Your Sleep Quality Down?

The question of why your body temperature goes up at night might be plaguing you, especially if you’re having trouble sleeping or keep waking up hot in the middle of the night.

Whilst it is completely natural for your body temperature to fluctuate, extremes in this fluctuation can cause you not to sleep well.

There are a number of reasons why your body temperature might spike at night, including your pre-sleep routine, bedding, certain medications, and medical conditions.

If you're curious as to why your body temperature goes up at night, or are seeking solutions to this problem, we discuss some possible reasons why your body temperature might go up at night.

Does Sleeping Affect Your Body Temperature?

The short answer to this question is undoubtedly, yes, being in a state of sleep affects your body temperature.

We all have something known as our circadian rhythm, and this plays a vital role in our sleep/wake cycle.

This internal body clock is also responsible for regulating your core body temperature. In any 24-hour period, your core body temperature fluctuates in a reasonably predictable way.

You might find that you feel colder in the evenings, this is normal as it encourages sleep. When you drift off, your body temperature continues to fall, which facilitates restful sleep.

This may be surprising, but a higher skin temperature translates to a lower core body temperature.

By diverting blood to the skin, your body is able to regulate its core temperature whilst you're asleep.

This regulation is happening continuously, your body adjusts your sweat rate and hormone levels along with blood flow to the skin in order to keep your body temperature at the optimum range for sleep.

Why Does My Body Temperature Go Up At Night?

With the above in mind, you might be wondering why you feel hot whilst you're asleep. As we've mentioned, there might be a few reasons why this is the case.

Clothing And Bedding

This might seem like an obvious point, but it is one worth considering. Both the clothing you wear whilst you sleep, and your bedding can play a role in your body temperature going up at night.

Your body naturally wants to cool down as you fall asleep, and wants to keep cool whilst you are asleep.

One way it does this is by sweating. Sweating stops you from becoming too hot, and as such your clothes or bedding might be interfering with your ability to sweat.

The Temperature Of Your Bedroom

There are many studies which support the idea of turning your heating off whilst you sleep. If your bedroom is too hot, this is likely to increase the amount of time you spend in bed awake.

Your circadian rhythms associate heat with being awake, so naturally, when your room is too hot you're more likely to stay awake.

When you do fall asleep, the temperature of your bedroom can affect the amount of time you spend in each sleep stage.

There are two stages of sleep which are essential to your emotional and physical health: deep sleep and REM (rapid eye movement) sleep.

If you sleep in a hot room, you are likely to spend less time in either of these stages.

Underlying Health Conditions Or Sleep Disorders

There are a number of health conditions which can impact your body's ability to regulate its temperature.

One such health condition is obstructive sleep apnea (OSA). OSA is a sleep disorder which prevents your body from achieving deeper stages of sleep.

It is common in those who are overweight, although it can impact anyone.

When someone with OSA is asleep, their upper airway can become constricted and narrow as they enter deep sleep stages, meaning that their body will naturally raise them out of these sleep stages.

People with depression also do not experience as much of a decrease in body temperature whilst getting to sleep.

Medications such as antidepressants and antipsychotics are also linked to night sweats and a higher temperature whilst asleep.

Women going through the menopause also often experience an increase in body temperature at night.

A decrease in the hormone estrogen during the menopause can lead to hot flashes and disturbed sleep.

The hot flashes can make going to sleep difficult, and can also wake you from sleeping if you feel like you are overheating.

Pre-Sleep Activities

This is worth considering as what you do before bedtime can increase your body temperature and disturb your sleep:

Exercise

Whilst exercise is a fantastic way to promote a good night's sleep, vigorous exercise undertaken within an hour of bedtime can have a negative impact on sleep.

Exercise raises your heart rate, and it will take time for this to settle before you can sleep.

Caffeine

This is well documented. Caffeine is a stimulant and as such consuming it before bed can make falling asleep difficult.

Sex

Whilst sex can improve sleep quality, as it releases hormones associated with relaxation, vigorous sex that raises your heart rate might have the same effect as exercise. Your heart rate will need to settle before you can sleep.

Conclusion

The list above is by no means exhaustive. There are other factors such as sleeping partners, different types of medication, and imbalances in hormones which could be playing an important role in waking you up at night because you're too hot.

It might be worth taking stock of some factors above, like checking the temperature of your bedroom. The optimum temperature of a bedroom at night is between 18 and 21 degrees.

Disruption to sleep can make you feel terrible throughout the day, and prolonged sleep disruption can lead to serious health problems.

The best advice anyone could give is that if you believe that you're experiencing some of the above issues, speak with a medical professional.