Beat the heat this summer

Summers are getting hotter and hotter, trends are showing that the temperature is increasing 0.2 °C (0.36 °F) per decade(1).  

In 2021 we experienced the warmest summer ever recorded.(2)

rising temperatures

Though many of us might appreciate more sunshine and warmer summers, the hotter nights make sleeping well difficult.

Too hot to sleep?

We have more tropical summer nights than ever and the warmer night temperatures can wreak havoc on our sleep quality.

A sleep study from UCLA in 2015 showed that ambient temperature might have more of an impact on our sleep duration than light. The study focused on the sleep of native people across the world and concluded that they sleep through the night while the temperature dropped and woke up when the temperature reached the lowest point of the day, even if this was past sunrise.(3)

 So what is the impact of temperature on our sleep?

  • To fall asleep our core temperature needs to drop. If we are too hot our sleep onset time, i.e. the time from wakefulness into sleep, increases as we toss and turn in bed.
  • To stay asleep we need to stay in the ideal climatic comfort zone during the night. If our temperature shifts outside of this comfort zone, our deep sleep and slow wave phases in particular are disturbed. In the worst case scenario we wake up but even if we sleep through our sleep quality is not as high as it should be.
  • If we overheat we start to sweat to cool down. This can lead to uncomfortable wet and cold sleepwear and bedding, as a result we then risk becoming cold and starting to shiver.
  • If we overheat our heart rate tends to go up not only impacting our sleep quality, but also our recovery rate, making us more tired the next day.

Swiss studies(4) have shown that we sleep 40 minutes less than 30 years ago and studies by SleepScore Labs(5) show that during the summer we sleep another 10 minutes less than during the rest of the year.

So what can we do to beat the heat?

Cool down, sleep better

There are a number of easy actions we can take to sleep longer and deeper during the summer.


Setting yourself up for a good night's sleep starts already during the day:

  1. Cool down your bedroom: Keep windows and blinds/ curtains shut during the day to prevent your bedroom from warming up.
  2. Exercise at the right time: Exercising increases our body temperature. For that reason it's always better to avoid doing sports just before going to bed. During the summer it's even more important.  
  3. Eat a cooling diet: If our digestive system is working at full speed during the night this will increase our heart rate and body temperature. By eating light meals at the end of the day we can set ourselves up for a better night's sleep.
  4. Keep hydrated: Make sure that you keep hydrated during the day, but avoid caffeinated drinks or alcohol just before going to bed.


Follow these tips to help our core temperature to drop:

  1. Cool down the bedroom: When the sun has set and temperatures have dropped, let the cool night air into your bedroom. For further evaporative cooling you can try hanging a damp or wet sheet in the window. The aim is to have a bedroom temperature that is no higher than 18°C / 64.5°F.
  2. Cooling sleepwear: Wear lightweight and breathable materials to avoid heat build-up. Opt for natural materials that normally are more breathable than synthetics.
  3. Cooling bed sheets: use natural materials that are light like from botanic fibres.


Stay cool throughout the night with the help of these tips:

  1. Cooling air flow: Keep the air flowing through the room with the help of a fan. For additional cooling you can keep a bucket of ice just in front of the fan to cool down the air. If night temperatures consistently are high you can consider installing air conditioning.
  2. The right mattress: Foam mattresses can trap heat so look for breathable, natural options that help to release excess heat.
  3. Space out in bed: Body heat from others is a great way to heat up. So if your aim is to cool down, then space out and make sure that pets and kids sleep in their own beds. 
  4. Cooling pyjamas: Wear lightweight, breathable cooling sleepwear to enjoy the best cooling night comfort. 

Summer pajamas


Dagsmejan Stay Cool collection combines cooling eucalyptus fibres with NATTCOOL™ technology to provide the ultimate cooling night comfort:

  • 8x more breathable than cotton
  • Dries in 1/3 of the time
  • 2x softer than cotton
  • Ultra-light

Dagsmejan summer pyjamas is designed to both avoid heat build-up and to help you cool down if your temperature rises:

  • Avoid heat build-up: Lightweight and extraordinarily breathable, Dagsmejan cooling sleepwear prevents heat to build up and if you get too hot, excess heat is released through the fabric.
  • Cool down: Dagsmejan summer pjs work on 2 levels to help keep you comfortably cool and dry should you start to overheat. If you start to sweat some of the moisture is stored in the core of the fibre, gradually being released into the environment thereby cooling you down with evaporative cooling. With the help of moisture-wicking you still feel dry and avoid getting cold and clammy.

SHOP Women's summer pyjamas

SHOP Men's summer pyjamas

Cooling summer pjs