We've all been there. You jump into your car and within a few minutes of driving the windows are so fogged up inside that you're looking at the world through a murky layer of moisture. How did that happen?
For the inside story, Cars.com spoke with Mike Hoppe, an engineer for Fiat Chrysler Automobiles in charge of climate control systems, who said windows fog up on the inside when warm, moist air in the car meets colder glass surfaces, causing condensation.
"In its simplest form, it's too much water in the air, and it condenses on the glass," Hoppe said. "It condenses on the inside because the outside is colder, and when it's colder outside that lowers the relative humidity point.
"It's like when you see your breath when it's cold outside. Your breath generally has 100 percent humidity in it, but you're only seeing it when it's cold outside because that's when it's reaching the point where it's causing fog."