Most drivers don't know about this little-known dashboard button, but pressing it can help cool your car down much faster in hot weather. Here's how to use the feature correctly12:32, 25 May 2026Updated 12:32, 25 May 2026Climbing into your vehicle during a heatwave can be a deeply unpleasant experience. The windows on every side of the car allow sunlight to flood in, warming up the interior while hot air becomes trapped inside, essentially transforming it into a compact greenhouse.‌Fortunately, most modern cars feature air conditioning, meaning you'll only need to endure the discomfort for a few minutes before it cools down, after which you won't want to get out.‌But what's the quickest and most efficient method to cool your car down? As it happens, the solution involves a button displaying a rather puzzling symbol.‌One man who frequently shares useful car-related tips on social media revealed more. The man, who boasts 128,000 followers on TikTok under the name Capturing Cars, explained: "99 per cent of people use this button all wrong, and maybe you're one of them."Gesturing towards the button, which shows an outline of a vehicle with an arrow looping back inside, he went on: "What does the button itself actually do? So, it is a recirculation button - essentially, it shuts off the vents to the outside of the car, trapping the air that's in it."Content cannot be displayed without consent‌He explained it works best when temperatures are either extremely hot or extremely cold. Demonstrating how to utilise the system alongside your vehicle's air conditioning to cool things down, he stated: "What you will want to do is press this button."That will then trap the air inside the car and it will get colder on each pass, or hotter if you've got the heating turned on, of course."If you don't have it on you are bringing in boiling hot air from outside and trying to make it cold essentially, and it takes a bit longer. It will happen, it just takes a bit longer. So turning that on will accelerate the process of cooling down the car."‌He went on to say it's best avoided on damp days, reports the Express. Elaborating, he explained: "Let's say you're in the car, you've got wet clothing because you've been caught out in the rain."If your car is fogging up, which let's face it, we've all experienced, that is when you'll want to turn this off. The reason being, you are trapping humidity inside the car. It can be from you breathing, it can be, say, from a wet umbrella or wet clothes, whatever it might be. But trapping humidity in is what causes fog on your screens."He noted that vehicles even have a function which deactivates the recirculation button when you direct air towards your windscreen to clear condensation. "The car itself is stopping you from doing it because it knows it will not work efficiently in getting rid of fog on your windscreen," he explained.Article continues belowCommenters shared additional uses for the feature. One remarked: "Another good time to use this is if you are following an old vehicle giving off loads of smoke, or if you are driving in the country and they have recently laid manure on the fields. It stops the smell. But ideally yes to heat [or] cool your car quicker."Another commented: "I always use recirculate. Keeps car exhaust out when I'm in traffic."However, another user sounded a note of caution. "On very long drives be careful about leaving the recirculation on too long as it can deplete oxygen in the car and make you sleepy," they warned. "Open the window every once in a while."