High temperatures, well into the evening, affect your body's natural cooling process as you prepare for sleep. "The body normally releases heat through hands, face and feet around the time of sleep onset, and usually continues to cool until around 4am," says Dr Chris Idzikowski, director of the Edinburgh Sleep Centre and author of Sound Asleep. "If anything prevents that decrease in temperature, then sleep quality is impaired and it is difficult to fall asleep." Although he also warns that at the point where your body temperature is at its lowest, you may wake up if you don't have enough bed linen to keep you warm.

Choice of bed linen is important (natural fibres are best) and if your mattress is made from foam or other synthetic materials: "Try using a mattress protector made from cotton wadding." Idzikowski also suggests keeping your pillow in the fridge during the day and retrieving it as you go to bed. Loose-fitting nightclothes (in cotton or silk) could be more effective than sleeping naked: "Natural fibres wick away moisture from your skin." Spreading out, rather than sleeping curled up, will help you keep cool.

Make sure there is good air circulation – either by using a ceiling or portable fan, or just keeping door and windows open. Others suggest preparing your bedroom, Mediterranean-style, by leaving blinds down or curtains closed during the day to keep the sun out, and opening your windows in the evening once the heat of the day has died down. Idzikowski says the ideal bedroom temperature is around 18C, though if you share a bed, your partner may prefer it to be cooler.

If you're in the grip of a sweltering insomnia, "run your wrists and hands under the cold tap for a few minutes. Dry your hands and go straight back to bed."

A nap in the day will help counteract the effects of lost sleep. "Any amount of sleep will be helpful," says Idzikowski. "You don't have to match what you've lost." For adults, he says, sleep is roughly composed of cycles lasting around an hour and a half: "So if you can get one and a half hours [catch-up nap], that's fantastic because the odds are you'll have had a whole cycle. But even if you reduce it to 30 minutes, the chances are the deep sleep will have happened and [you get] a lot of recovery from that." Remember, he says: "One of the things that prevents somebody going to sleep is worrying about not sleeping. So try not to panic about it."