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Which is healthier: sleeping with the window open or closed? Find out the pros and cons here!

10 May, 2024
Jürgen Swinnen

Sleep with window open or closed? It seems like a trivial question, however the implications of the answer are not. Awareness about the impact of bedroom temperature on sleep is an important factor that has been underestimated by a lot of desires.

Sleeping with an open window is beneficial for air quality and the amount of oxygen in the room. And at the same time, it’s really important to consider the temperature of the room as well. It is sort of balancing between fresh air and a pleasant temperature. Venting briefly and vigorously in the morning after waking up, closing windows during the day and opening or ajar again just before you go to sleep: this is often better for the temperature in the bedroom.

morning awakening

Does a cooler environment help you sleep better?

The answer is: yes! Our internal biological clock regulates various body processes, including body temperature. This 24-hour rhythm affects our sleep-wake cycle. Completely automatic, you don’t have to do anything for it.

The distinction between core temperature and skin temperature is important here. In fact, the body always prioritizes core temperature because our lives literally depend on it. The skin responds to temperature changes and will always monitor its core temperature, through recognizable processes such as shivering and perspiration, which is essential for temperature regulation.

Our internal biological clock automatically lowers the core body temperature in the evening hours. This is how the body prepares for the upcoming night. Your body uses less energy as a result. Your heart rate and blood pressure drop and melatonin is released. Therefore, a cooler environment is better for your body. Ideally, the bedroom temperature should be 18°C.

Sleeping with windows open or closed: The impact of temperature

So a cooler sleep environment helps you fall asleep more easily. Does this mean then that it is best to always sleep with the window open? No, that answer is a bit more nuanced because be careful not to get too cold.

Can you sleep with windows open in winter?

The ideal bedroom temperature is 18°C, so even during the winter months. From the moment it gets colder than that ideal temperature, unwanted effects arise. Consider memory foam mattresses, also known as memory foam. From that, pillows, mattresses or toppers become firmer, sometimes even hard. In the case of thermoregulating materials, such as gel, the products do sometimes become very cold, making it just less easy to fall asleep.

Cool temperature when sleeping

The duvet or blankets under which you sleep are best adapted to the bedroom temperature. Thinner in the warmer spring and summer months and thicker in the winter. Just like your bed textiles, because in the winter months a flannel cover can serve you just fine, while in the summer you prefer to sleep under a cotton satin or cotton percale cover. And if it is very hot maybe even only under a silk sheet.

Another important factor is the air in your sleeping space. Cold air can absorb much less moisture and so condensation can occur. The bed, bed textiles and mattress get damp even before someone sleeps in them. If you don’t like changing duvets in seasons, air conditioners and heaters are smart choices. This way you always keep the temperature constant.

And what about sound?

An open window or a window ajar … it already makes a difference with respect to noise. Do you live in a rural area with little ambient noise, or is your bedroom on a busy thoroughfare near a village center? Sometimes you don’t even have the choice and close the windows for the sake of noise. Unless you’ve gotten used to it, of course.

Our sleep is super-intelligently regulated and evolved over time. Most people get used to certain sounds and will not wake up to them either.

That’s because our brain doesn’t catalog them as dangerous and so you sleep peacefully on. Sleep is all about safety and security.

A small portion of the population experiences very light sleep. Throughout history, these were very important protectors during the dark nights. Because back when we were not sleeping in our lovely beds, but on the ground somewhere in a forest, surrounded by dangerous predators…. You can imagine how glad you were then that someone warned you in time for upcoming danger.

Conclusion: Will you sleep with window open or closed?

A well-ventilated bedroom is crucial for a healthy sleep environment, there is no pin in that. Opening windows provides fresh air and can improve air quality. However, especially in colder periods, it is advisable to always close the windows again during the day to allow the room to warm up to the optimal temperature of 18 degrees. This helps create an ideal sleeping environment without the drawbacks of cold drafts and external noises.

Just before bedtime, of course, the window can be opened again, usually ajar. Bed, mattress, duvet and pillow will then not get damp nor feel too hard or cold.

Mindthebed.com answers frequently asked questions:

Is sleeping with the window open healthy?

If the bedroom temperature remains healthy, around 18°C and you are not bothered by ambient noise, sleeping with the window open or ajar is good for ventilation and aeration.

How long should you open the window to air out?

For half an hour, opening all bedroom windows and doors is sufficient to forcefully ventilate the room. It is best to do this just after waking up.

What’s better with warm weather: Windows open or closed?

During hot summer days, it is best not to let direct sunlight in during the day. So close curtains, net curtains or blinds after airing. Keep the heat out. Does it cool down during the night and is the ambient noise not too bad? Then, in addition to your window, open the connecting doors in your bedroom to create an airflow.