Motorists are at risk of being slapped with a £5,000 fine for failing to press a button on their car dashboard this month. A leading expert has warned drivers are at risk of "breaking the Highway Code" if they don’t turn on their air conditioning in hot weather due to a simple rule.

Louise Thomas, motor insurance expert for Confused.com stressed the switch was crucial to help drivers "avoid drowsiness" while behind the wheel. The start of summer could be one of the most dangerous times with temperatures set to soar in the coming days. According to the Met Office, temperatures could hit 26C in London on Wednesday, with the warmer weather to remain well into the following weekend.

Louise previously explained: "Not using air-con or putting the window down in hot weather could see drivers break the Highway Code, as motorists must keep their cars 'well-ventilated'."

According to the expert, this rule is paramount in helping drivers avoid drowsiness when operating a vehicle, with potential penalties looming for those who ignore it.

"This rule helps to ensure drivers avoid drowsiness when in control of a car and breaking this rule could result in an on-the-spot fine if you are deemed to be driving carelessly or involved in an accident as a result of poor ventilation."

Careless driving is considered very serious and could see individuals charged with driving without due care and attention.

However, owners of more modern vehicles may be able to access the settings using their built-in infotainment system.

Experts at BigWantsYourCar added: “Good ventilation is essential for safe driving. Without adequate airflow, car interiors can overheat rapidly, leading to fatigue and reduced awareness.

"Opening a window or using air-con can make a significant difference to your concentration levels on longer journeys.”