https://windowmedicsottawa.blogspot.com/2022/08/here-are-some-effective-tips-for-dealing-with-foggy-windows.html

Regardless of where you reside, keeping the temperature comfortable inside your car typically involves battling cloudy windows. If you live in a cold-weather location, staying warm in your automobile means turning on the heater — and fighting the resulting fog on the inside of your windows. In hot, humid climates, turning on the air conditioner might have the opposite effect, obscuring your windows from the outside.