Why you should NEVER sleep with a fan on overnight during the heatwave: Experts reveal air blowing can trigger allergy and asthma attacks
With much of England set to sizzle in highs of up to 90F today, many will be turning to their electrics fans in a desperate bid to cool down come bedtime.
But while fans are an ideal way to stay cool for short periods of time, keeping them on all night may have several negative impacts on your health, according to Sleep Advisor reports.
And it's not good news for those who suffer with allergies or asthma because dozing off with a fan on could end up circulating not just air - but pollen and dust as well.
The Sleep Advisor says: 'Take a close look at your fan. If it's been collecting dust on the blades, those particles are flying through the air every time you turn it on.'
Leaving a fan on all night can also have bad consequences for your skin - leaving it feeling and looking dry.
The constant airstream can also have the same affect on your eyes and mouth - especially those who sleep with them partially open.
Sleep Advisor also warned the cool air could result in you waking up in the morning feeling stiff - particularly those who position the fan on their neck and face.
'This is because the concentrated cool air can make muscles tense up and cramp,' the experts explained.
Britain is set to face yet another scorching day, with an extreme weather warning for 90F temperatures today after thunderstorms swept across the country and brought two inches of rain on the hottest day of the year so far.
The Met Office says mercury is expected to push 86F across southern England and 77F in Belfast, with temperatures forecast to be cooler in the east.
Sun-seekers are warned to beware of sunburn, heat exhaustion, dehydration, nausea, fatigue 'and other heat-related illnesses'.
It comes as England reached its hottest temperature of the year on Tuesday - 89.96F - recorded at Heathrow Airport in west London.
The previous high for the year was 88.88F, which was also recorded at Heathrow on Sunday.
An amber extreme heat warning remains in place for central and southern England, Wales and Northern Ireland.