Why do you need to turn on the air recirculation button when getting into a car for 15 minutes, and only on a cold road

The car alarm system is not only useful for starting the engine, but also for ending it. However, car owners do not often think about the fact that it also works in reverse, that is, it can be used to get into the car and start the engine while the passenger is inside. Actually, the idea of using it in such a situation is quite novel. The secret of turning on the recirculation system in the car is not to get into the passenger compartment or trunk, but to stay inside the car and listen to the sound system. So this secret will come in handy not once, but three times: in the morning, when you need to get out of the car, you don't have to go outside, as it will be too cold to open the trunk; at night, when the passenger compartment can be very cold; when the windshield wiper blades become dirty and it's time to change them. And how do you like this secret? , SHARE in social networks, COMMENT.