Never leave the windows up when turning on the car's air conditioning. The driver's manual states that before turning on the air conditioning, you should open the windows and leave them open for at least three minutes or more, but it doesn't specify why—just that it is for "better performance."
WHY?

The refreshing air emits Benzene, a toxin that causes cancer (carcinogenic agent—it takes time to notice the smell of heated plastic in the car).

In addition to causing cancer, Benzene poisons your bones, causes anemia, and reduces white blood cells. Prolonged exposure can increase the risk of cancer.

It can also cause a miscarriage. The appropriate level of Benzene in closed areas is 50 mg per 929 cm².

A car parked in a garage with the windows closed can contain 400-800 mg of Benzene. If it is outside under the sun with a temperature above 16°C, the Benzene level can rise to 2000-4000 mg, 40 times the acceptable level...

People who get into the car with the windows closed will inevitably inhale excessive amounts of this toxin, which is why it is recommended to turn on the air conditioning with the windows down so that the accumulated toxins can be released.

Benzene is a toxin that affects the kidneys and liver and is extremely difficult for the body to expel.