Dr Chris Idzikowski, director of the Edinburgh Sleep Centre and author of Sound Asleep , said that the body releases heat through hands, face and feet around the time of sleep, and continues to cool till around 4 am.
He said that if anything prevents that temperature decrease, then sleep quality is harmed and it becomes difficult to go to sleep, the Guardian reported.
Idzikowski, said that choice of bed linen is important, asserting that the natural fibres are best.
He said that if mattress is made of foam or other synthetic materials then people should try using a mattress protector made from cotton wadding.
Idzikowski suggested that people can keep their pillow in the fridge during the day and retrieve it as they go to bed.
He also said that loose-fitting nightclothes (in cotton or silk) are more effective than sleeping naked, as natural fibres absorb moisture from skin.
Spreading out, rather than sleeping curled up, also helps people stay cool, he said.
He added that if a person is in the grip of a sweltering insomnia they should run their wrists and hands under the cold tap for a few minutes then dry them and go straight to bed.