**Science Offers Relief: Hannah Fry Reveals Ingenious Car Cooling Hack**
As temperatures across the UK reach uncomfortable peaks this summer, motorists up and down the country are searching for inventive ways to keep their cars bearable in the sweltering heat. Stepping into a parked car that’s been baking under the sun can be as stifling as walking into a greenhouse. Yet, British mathematician and broadcaster Hannah Fry has sparked widespread interest with her unexpectedly simple science-backed technique to rapidly cool your vehicle — and it doesn’t involve switching on the air conditioning.
In a recently shared Instagram video, Professor Fry provided her followers with a step-by-step demonstration of her unconventional, yet remarkably effective, solution for releasing hot air from a car. Rather than relying on power-hungry air conditioning systems, Fry’s approach involves a combination of lowering the nearside window and manually swinging the driver’s door open and closed several times.
Explaining the science behind the trick, Fry said: “The reason why it works is that when you open and close the door, especially if you do it quickly, the door as it’s moving outwards sweeps out all of the air that’s in its way, creating this area of low pressure that you get here.” This sudden movement sets up what is scientifically referred to as ‘bulk flow’. In effect, each rapid motion of the door draws out the trapped, overheated air from inside the car and prompts a wave of fresh air from the window to rush in.
For those unfamiliar with the terminology, bulk flow is a principle from physics describing the movement of fluids (in this case, air) from an area of high pressure to lower pressure. In Fry’s method, swiftly opening and slamming the door several times creates a low-pressure pocket, and the temperature equalises as cooler external air replaces the oppressive heat trapped within the car’s cabin.
Fry suggests that after “just two or three goes,” occupants will notice a dramatic drop in interior temperature. “It only takes two or three goes and then suddenly it’s beautifully temperate,” she assures viewers, striking hope for those battling with heatwave conditions.
The method is particularly appealing to drivers concerned about fuel efficiency. Air conditioning is known to put a heavier load on the engine, slightly increasing fuel consumption. Amid widely reported rises in fuel prices, this approach allows drivers to save both energy and money, all while making the re-entry into a parked car significantly more comfortable.
It’s worth noting that many existing car models lack advanced climate control or ventilation features found in luxury vehicles, meaning this low-tech solution is accessible to virtually anyone. Moreover, Fry’s trick requires no specialist tools, apps, or additional gadgets — only the coordination to open and close your car door quickly and safely.
This practical advice comes at an opportune time, as the UK braces itself for continued bouts of hot weather and forecasters warn of potential disruption caused by prolonged heatwaves. With public health officials also raising concerns about the risks of excessive heat exposure in confined spaces, any trick that brings a quick cool-down is sure to be warmly welcomed.
While the hack may appear straightforward, its viral spread on social media highlights just how eagerly drivers share and adopt even the simplest solutions during challenging weather. As scientific know-how meets day-to-day inconvenience, Fry’s suggestion reinforces the value of understanding basic physics — and reminds us that sometimes, sensible advice can be found in the most unexpected places.
In summary, the next time you return to a sun-soaked car and dread reaching for the ignition, remember Hannah Fry’s science-approved technique. With only a rolled-down window and a brisk arm workout, you can transform your vehicle’s environment within seconds, making your journey — and the rest of your day — far more pleasant.