Doctor explains why sleeping with the windows closed could be ruining your sleep

With daylight savings now in effect, and the nights getting longer, darker, and colder, many people will be keeping the window firmly closed at night.

It's not like the summer when you can savour the cool breeze as you make increasingly futile to persuade your clammy body to go into snooze mode.

Now, things are finally cool enough to get nice and cosy under the duvet.

The prospect of opening the window when it's cold outside might seem like insanity, especially when you have to get up while it's still pitch black and freezing outside.

According to one doctor leaving the window closed at night could have a negative impact on how you sleep.

It's worth noting that there are a lot of other factors with sleep as well, like your mattress and pillows, screen time before bed, or eating late at night.

But, having the window open could also be a factor when it comes to getting enough shut eye.

Dr Eric Berg took to TikTok to share why this is exactly, and I'm sure many readers may have made a pretty close guess by this point.

Kinga Krzeminska / Getty

If you guessed that it was because closing the window means there will be less oxygen and more CO2 in the room, congratulations, you are bang on the money.

Dr Berg explained: "You're in a room when the windows are not open and you're not getting enough oxygen, because maybe you don't also have enough plants in your room which give you oxygen, you may have a tendency to have more CO2 in that room.

"And just that alone can affect your sleep in a negative way. This is why, when you open the window if you can, or you get a plant next to where you're sleeping, you can definitely sleep better just for the fact that you're increasing the oxygen and you're lowering the CO2.

TikTok / Eric Berg

"So many people are spending all day in a room with a higher level of CO2 and not enough oxygen."

Fortunately, if the thought of opening the window in the winter months has you shivering despite wearing four layers and being under two blankets, fear not.

There are alternatives to reducing the amount of CO2 in your room.

That is, of course, getting a plant to put into your room.

However, if you are the sort of person who only has to look at a plant for it to start shrivelling up, then sadly opening the window may be the only option.