What causes condensation?

If warm moisture that is carried through the air meets a cold surface, condensation occurs.Carrying out tasks such as putting your car heating on and even BREATHING can cause the fog to form. On a cold day, the warmth from your breath can cause water particles in the air to turn to steam, misting    up glass surfaces.

How do I prevent condensation on car  windows?

 There are ways to stop the mist from forming
If you prevent moisture from lingering in the confined space, windows are less  likely to mist up.

 Leaving windows slightly open on warmer days, and closing them when it’s raining, are ways to keep condensation at bay.

Removing sources of moisture from your car can also prevent your windscreen heated wiper blades from misting up.Anything that is damp will release water particles into the air, which will then turn to steam and cause dew to form on the glass surfaces.