A mathematician and presenter has shared a hack to quickly cool your car in a matter of moments. Hannah Fry recently posted on her Instagram account a video demonstrating how to make the interior of your car instantly cooler. Instead of turning on the air conditioning, it involves rolling down one of the windows on the nearside of the vehicle, and then you very quickly open and close the driver鈥檚 door multiple times. Fry said on her Instagram Reel: 鈥淭he reason why it works is that when you open and close the door, especially if you do it quickly, the door as it鈥檚 moving outwards sweeps out all of the air that鈥檚 in its way, creating this area of low pressure that you get here. And, then that sets up something called 鈥榖ulk flow鈥, which is where all of the hot, sweaty, horrible air inside the car is drawn outwards, and the only way to refill it is with nice fresh air from over on the other side.鈥 She added: 鈥淚t only takes two or three goes and then suddenly it鈥檚 beautifully temperate.鈥 This top tip should save you time in making your car鈥檚 cabin a lot cooler in the UK鈥檚 current heatwave.