Which air circulation mode should be used when the car interior fogs up?

[AutumnLee]

Turn on the external air circulation when the car interior fogs up. Additional information about external air circulation: 1. The external circulation mode uses a fan to draw outside air into the vehicle cabin, creating airflow between the exterior and interior. The air blown by the fan comes from outside the vehicle. Even when the fan is off, moving air is still drawn into the cabin while driving to replenish fresh air. Sometimes you may feel airflow even with the fan off - this occurs when external circulation is activated. 2. After entering the vehicle, you should open windows or activate external ventilation briefly to introduce fresh air. Avoid prolonged driving with closed windows and doors, and never sleep or rest for extended periods in a completely sealed vehicle.