There's nothing better than a warm, sunny day during the summer.
But there's nothing worse than a muggy summer evening, when it's so hot you struggle to get to sleep.
We've all been there - striping down to our underwear, kicking off the covers and opening all the windows.
Although it turns out the heat might not only be making us feel physically uncomfortable at night.
It could also be having an impact on our dreams - or more specifically our bad dreams.
Dr Neil Stanley, former chairman of the British Sleep Society has revealed exactly how the heat increases our chances of having a nightmare.
"In order for us to get a good night's sleep, we need to lose around 1C of our internal body temperature, which sits around 37C," he told MailOnline .
"We typically lose that through our head or face, which pokes out of the duvet.
"If you're sleeping in a room which is too warm, your body's core temperature is unable to lose that heat and your sleep will be disturbed."
He added that if our sleep becomes so disturbed that we are sleep deprived, we will see greater 'sleep intensity', which leads to greater brain activity.
This activity causes people to experience a phase of sleep called REM, making dreams more vivid and enabling us to remember them clearer.
It can also cause dreams to become more unpleasant, leading to nightmares.
Dr Stanley also commented that sleeping at the right temperature can help improve snoring and prevent other disorders such as sleep apnoea.
Ways to keep your bedroom cool and improve your sleep
1. Invest in cotton sheets
2. Stick your sheets in the freezer for a few minutes
3. Freeze your hot water bottle and stick it in your bed a little while before you go to sleep
4. Point your fan towards and open window to push out the hot air
5. Turn all the lights off
6. Close the curtains
7. Unplug your electronic devices and don't charge them while you sleep
8. Try hanging a wet sheet in front of an open window
