Why do car windshields get frosty in winter?

In this episode we talk about how moisture in the air turns into frost in the morning as the temperature of air drops overnight. We also talk about the freezing point and melting point of water and other material. To melt ice and frost we can add a little bit of alcohol to the the ice. That lowers its freezing point and makes it melt. This is how the anti-frost spray works.