Answer: this is as a result of DEW POINT.
Explanation: Dew point is defined as the temperature at which the air becomes saturated and water vapor condenses to form dew.
Glasses will fog up whenever you go from one environment to another where the dew point is met. When the temperature falls below this point moisture in the air condenses and causes the fogging of your glasses.
A mixture of prehistoric fossil and also known as fossil fuel and its it also carbon, sulfur and compressed oxygen