Parts of the UK have been battling with scorching temperatures during the intense heatwave recently, and because of that many Brits have been struggling to sleep due to the humidity, bringing on warm, sticky nights.
Even those who have managed to sleep may have noticed that they still feel tired and fatigued the next day, which is apparently normal during the summer.
A doctor previously explained that our bodies have to work harder in the heat in order to cool us down, and "fatigue is a normal response to heat, and is typically temporary".
So now the heatwave has ended, things will go back to normal right? We'll suddenly have loads of energy? That's not necessarily the case. If you've not shaken off the heatwave tiredness yet, you're not alone.
According to a doctor, the reason you still feel sluggish and exhausted, even now the mercury has dropped, you could be suffering from "sleep debt".
Dr Guy Meadows from Sleep School explained that while most people aren't achieving as much sleep as they need anyway, a heatwave could mean you go "above and beyond" your "normal sleep debt".
He explained: "Nearly three quarters of the population walk around with a sleep debt anyway – as in they're not achieving their biological sleep need, which is roughly seven to eight hours a night for most of us. So we can all already do with sleeping a bit more, but during the heatwave, we were struggling to sleep even more."
The doctor explained that while we're awake a brain chemical called adenosine builds up in our systems which helps create a "sleep drive," meaning we're ready to drift off come bed time.
He continued: "The more adenosine you have in your system, the more sleepy you feel. If you then get your eight hours of sleep, your adenosine is metabolised from the brain, and you wake up feeling refreshed."
However, if we don't get enough sleep to metabolise the chemicals, it means we wake up feeling groggy, which he explains is the "sleep debt effect".
Luckily, you can reverse the sleep debt, but the doctor doesn't recommend having a huge sleep to solve it.
Dr Meadows said: "The great thing is you can repay a sleep debt. But what I would definitely not recommend is people go and have a big, long lie-in, because what that does is cause 'social jetlag'. Put simply, big lie-ins 'upset' our circadian rhythm or natural 'body clock', which also leads to ongoing grogginess."
Instead, Dr Meadows advises to "repay your debt in small chunks over a period of time". That means, if you're tempted to have a lie-in in the morning, do it for "no more than one hour maximum".
If you want a nap, he recommends doing it after lunch, and for no more than 15 to 20 minutes. Another thing that can help is going to bed 30 minutes earlier than normal. He added: "Little catch-up opportunities over the next week will help restore the debt."
In addition to sleep debt, you're likely also tired because heatwaves are hard work on our bodies - you might have spent more energy than usual, and maybe even been a bit dehydrated.
GP and mental health coach Dr Hana Patel said: "As a GP, I often have people asking me why they feel more tired in hot weather.
"We sweat more in hot weather, as this process allows our skin to cool when the sweat evaporates. Another of our body's natural physiological responses is to allow more blood to flow to the surface of the skin, to release heat. Both of these actions take up a lot of energy, increasing our heart rate and burning calories, making us feel extremely tired and sleepy."
While the worst of the heat might be over, it's still warm, which means our bodies are still adjusting.
Do you have a story to share? Email us at yourmirror@mirror.co.uk
