Too hot to sleep? At this temperature your sleep really suffers

Summer, sun, long evenings – actually the perfect time to relax. But while we enjoy warm days, hot nights become a challenge for many people. They toss and turn in bed, wake up sweaty, or feel completely exhausted the next morning despite getting enough sleep.

No wonder: Our sleep is closely linked to body temperature. If it gets too warm at night, the body can no longer optimally carry out important sleep processes. The result is difficulty falling asleep, frequent awakenings, and less restful nights.

But at what point does it actually become too hot to sleep? And what really helps against warm summer nights?

Table of contents

1. Why heat disrupts sleep
2. The ideal sleeping temperature
3. At what point does it become too hot?
4. What happens in the body when it's hot
5. Which sleep phases are particularly affected
6. Who is particularly affected
7. The best tips for hot nights
8. Conclusion

1. Why heat disrupts sleep

To help us fall asleep, our body lowers its core temperature in the evening. This natural cooling process is one of the most important signals to our brain that it's time to sleep.

To achieve this, the blood vessels in the hands and feet dilate, among other things, so that heat can be released into the environment. However, if the bedroom is too warm, this process works significantly less effectively.

The body has to expend more energy to regulate its temperature. Instead of focusing on rest, it's working against the heat – and that's precisely what can disrupt sleep.

2. The ideal sleeping temperature

Sleep researchers recommend a bedroom temperature between 16 and 19 degrees Celsius for most adults.

In this area, the body can regulate its temperature particularly efficiently. At the same time, it supports natural cooling, which is important for falling asleep and staying asleep.

Of course, there are individual differences. Some people prefer it a little warmer or cooler. Nevertheless, studies repeatedly show that a cooler sleeping environment can improve sleep quality.

However, these values ​​are often significantly exceeded, especially in summer.

3. At what point does it become too hot?

Many people notice that they sleep worse even at temperatures around 24 to 25 degrees.

Typical signs include:

• falling asleep more slowly
• frequent waking
• night sweats
• restless sleep
• Tiredness the next morning

From around 26 degrees Celsius room temperature, the strain on the body often increases significantly. Temperatures above 28 degrees Celsius can noticeably impair sleep for many people.

Especially during heat waves, the body lacks the opportunity to recover sufficiently overnight. This can lead to a build-up of sleep deprivation over several days.

4. What happens in the body when it's hot

When it gets too warm at night, the body activates various mechanisms to protect itself from overheating.

This includes:

• increased sweating
• increased skin blood flow
• higher heart rate
• increased fluid loss

These processes are important for maintaining a stable body temperature. At the same time, however, they ensure that the body remains more active, even though it should actually be at rest.

Additionally, heat and sweating often lead to brief awakenings. Many people don't remember this in the morning, but sleep quality still suffers.

5. Which sleep phases are particularly affected

Heat primarily affects sleep phases, which are especially important for our recovery.

This includes deep sleep and so-called REM sleep.

Deep sleep supports, among other things:

• physical regeneration
• Muscle building
• immune system
• Metabolic processes

REM sleep, on the other hand, plays an important role in:

• Learn
• Memory formation
• emotional processing

People who wake up frequently on warm nights often spend less time in these crucial sleep phases. Therefore, many people don't feel truly rested the next day, even after getting enough sleep.

6. Who is particularly affected

Heat can generally affect anyone's sleep. However, some groups are particularly sensitive.

This includes:

• older people
• Babies and toddlers
• People with cardiovascular diseases
• Overweight people
• People with sleep disorders
• Women during menopause

Even people who generally sweat more or are very sensitive to temperature often notice even small temperature increases significantly.

7. The best tips for hot nights

Even without air conditioning, there are several ways to make the sleeping environment more comfortable.

These measures have proven particularly effective:

Keep the bedroom cool

Ventilate as early in the morning or late in the evening as possible. During the day, windows, curtains, or blinds should remain closed to keep the heat out.

Choosing the right materials

Lightweight bedding made of cotton or linen can help wick away heat and moisture more effectively. Breathable pillows and duvets can also improve sleep comfort.

Avoid alcohol and heavy meals

Both of these things put additional strain on the body and can make temperature regulation more difficult.

Drink enough fluids

Those who consume enough fluids throughout the day can better compensate for fluid loss through night sweats.

Take a lukewarm shower instead of an ice-cold one.

A cold shower may feel pleasant at first, but it can stimulate the body to produce more heat afterward. Lukewarm water is usually the better choice.

8.Conclusion

• The optimal sleeping temperature for most people is between 16 and 19 °C. Sleep quality can noticeably decline at temperatures as low as 24 to 25 °C.

• High temperatures make it more difficult for the body to cool down naturally, which is important for falling asleep and staying asleep.

• Deep sleep and REM sleep are particularly affected by heat, thus impairing nighttime recovery.

• A cool sleeping environment, breathable materials and the right evening habits can improve sleep quality even in summer.