Experts have revealed why you should not sleep with a fan on overnight despite extreme temperatures amid a UK heatwave. 

The Met Office has issued an extreme weather warning until Sunday with highs of around the mid-30s.

High temperatures will also be seen in Scotland and Northern Ireland as some parts of the UK will be hotter than the Caribbean.

As Brits grapple with sizzling heat attention turns to sleeping, many will opt for a bedside fan to help drift off in boiling temperatures.

However, experts have warned keeping a fan on overnight can have a negative impact on your health, particularly if you suffer from allergies and/or asthma.

Sleeping with a fan on could end up circulating pollen and dust into the albeit cooler air.

One expert explained how “concentrated cool air can make muscles tense up and cramp”. It can also dry up your nasal passages which could result in your body producing more mucous and leave you feeling blocked up when you wake up.

Experts have warned to take a close look at your fan. If it’s been collecting dust on the blades then that dust will be circulating overnight.

But in more positive new for those who struggle to sleep at night in hot temperatures, the Met Office predicts the sizzling temperatures won’t last too long.

The Met Office said: “A cold front from the north introduces more uncertainty on how long the highest temperatures will hang on for Saturday, with areas to the southeast currently most likely to hold on to warmth the longest, although the extent of this is still being determined.”