Cool a boiling car in seconds with ‘hidden’ car key trick

Many modern cars are equipped with a special feature that can help cool down your vehicle

Climbing into a car that’s been baking in the blazing sun all day can be among the most unpleasant aspects of a heatwave. Yet many motorists are unaware that their car key may already contain a built-in function that can help cool down the vehicle before they slide behind the wheel.

It follows the Met Office issuing a red weather warning for heat impacting various parts of the UK over the past week, with temperatures soaring as high as 38C. Drivers have been seeking ways to best prepare for their journeys, and it appears the solution isn’t overly complicated.

Pressing and holding the unlock button on many car keys automatically lowers all of the windows simultaneously. By allowing the hot air to escape before you even open the door, the interior of the vehicle can start cooling almost straight away.

The feature, also referred to as ‘global opening’ or ‘convenience opening’, is available on numerous modern vehicles, though it isn’t fitted to every make or model. Motorists are advised to consult their owner’s manual, as some manufacturers require the feature to be activated through the car’s settings.

This trick proves especially handy during spells of hot weather, when the temperature inside a parked car can climb far more rapidly than the air outside. According to the RAC, opening windows and doors before setting off is one of the most effective ways to release trapped heat and boost airflow.

The AA also advises ventilating a hot car before driving off, rather than depending entirely on air conditioning. It suggests that allowing the stifling air to escape first can make the cooling system work more efficiently and enhance comfort at the wheel.

The guidance comes as parts of the UK continue to endure exceptionally high temperatures. The Met Office warns that heatwaves can create hazardous conditions inside parked vehicles, where temperatures can soar considerably higher than those recorded outdoors.

While the little-known window feature can help make a car’s interior more bearable, it should never be treated as a replacement for proper heat safety precautions. The NHS advises steering clear of prolonged periods in hot, enclosed spaces wherever possible, and emphasises the importance of keeping cool and drinking plenty of fluids during extreme heat.

Experts also urge drivers never to leave children, elderly people or pets inside a parked car, even briefly.

According to the RSPCA, temperatures inside a vehicle can reach fatal levels within minutes, even if a window has been left slightly ajar.