Experts have revealed why nobody should sleep with a fan on overnight despight extreme temperatures amid a UK heatwave. 

Temperatures soared into the high 30s in some areas on Monday, while Tuesday is predicted to be even hotter, with temperatures possibly reaching 40C (104F).

That would be a new record for the UK, beating the 38.7C (101.7F) seen in Cambridge in 2019.

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 news 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, with areas to the south east currently most likely to hold on to warmth the longest, although the extent of this is still being determined.”