As all drivers know, a foggy windshield isn’t just a nuisance—the low visibility can also make driving more dangerous. In the video below, Rober explains that the general goal is to swap out the humid hot air with dry air that can absorb moisture. In other words, crack your windows (weather permitting), keep the “air circulation” button turned off, and crank the heat. Rober has a couple tips for keeping your windows fog-free in the first place, too. And while anti-fog spray definitely does the trick, Rober found that wiping your windshield with shaving cream is just as effective.