In news that will come as little surprise to anybody trying to get to sleep this week, researchers have found sixty two per cent of people struggle to sleep during warmer weather.
"The problem with sleeping in the heat is that in order to get a good night's sleep, you need to lose around one degree of body temperature during the night," says sleep expert Neil Stanley, author of How To Sleep Well.
"Usually that's not a problem and in regular weather, this happens naturally as we lose heat from our head and face throughout the night. But when the temperature heats up, it's harder for our bodies to shift this heat and so we struggle to fall asleep and stay asleep."
Nick Littlehales, a sleep coach to some of the world's biggest sports stars, says another reason we struggle to sleep in the heat is that we're simply not used to it.
"The natural circadian rhythms of the day—the sun up and the sun down process—is about moving from a normal body temperature to a cooler environment as the sun disappears", he explains. "When you're exposed to heat throughout the day and into the late evenings, that warm temperature is counter-intuitive to going into sleep."
"In the UK, we're always surprised when it snows in winter and when it get hot in the summer," says Neil Stanley. "We're the least prepared country when it comes to dealing with any fluctuations in weather." So what's the solution?
Get a fan
"Invest in either a tall, floor standing fan, or just use your desk fan," says Neil. "This will get cool air circulating around the room, which will cool you down. Or better still, put a pack of frozen peas in front of the fan so you get icy blast of cold air."
"I knew one athlete who would put two litre bottles of water in the freezer, put them in a bowl in front of a fan and let the fan blow over the cold bottles. It seemed to work for him," says Nick.
As tempting as it is to cool down with a few cold beers or cocktails after a hot sunny day, limit yourself; "As well as containing a lot of calories which require body heat to burn off, too much alcohol in the evening will leave you dehydrated, hot, bothered and sticky, which isn't conducive to good sleep," says Neil.
Keep windows closed
"Opening windows just lets hot air in, yet people do it in the mistaken belief it will cool the room down," says Nick. "Instead, you should keep your bedroom curtains and windows closed to keep the hot air and sun out. Make your bedroom as dark as possible."
"The other issue with sleeping with your bedroom window open in the heat, is that it increases noise in the bedroom, and it may make you anxious about a burglar coming in," says Neil. "And you need a quiet mind, and to feel safe and secure, to sleep properly. Anxiety is even worse for sleep than heat."
Keep your pillow cool
"A lot of body temperature comes from head temperature, so a cool pillow can help," says Nick. "Shoving your pillow in the freezer works. Freezer blocks you would use to keep a cooler bag cool during a picnic can be handy too. Put them in a bag and inside the pillowcase, on the underside."
Use a hot water bottle (yes, really)
"It's not a hot water bottle, it's simply something to hold liquid," says Nick. "Put freezing cold water in your hot water bottle and put it inside your bed."
Ditch the duvet
"Forget about summer or winter duvets and just ditch your duvet and top sheets altogether," says Neil. "Instead, wear 100% cotton pyjamas, which will wick away sweat during the night and keep you cool."
Have a light dinner
"Anything too calorific will need to be burned off by the body, which creates heat and adds to the problem," says Neil. "So go for less calorific meals in the evening and you'll find it easier to fall asleep."
"Anything carbohydrate-heavy will continue to be digested by the body, which creates internal temperature," says Nick. "So heavy meals are out; keep it light with salads, fruit and similar foods."
Lastly, have a positive attitude
"We all know sleeping in the heat can be a bit of a bother, but we seem to manage just fine on holiday, even when we don't have air conditioning," says Neil. "Worrying about getting to sleep is one of the biggest obstacles to good sleep. So enjoy the weather and pretend that busy road outside your house is a lovely Thai beach. You'll be sound asleep in no time..."
How to Sleep Well by Dr. Neil Stanley is published by John Wiley and Sons Ltd (rrp £10.99). To order your copy for £9.99 plus p&p call 0844 871 1514 or visit books.telegraph.co.uk