It is a complex process of transformation and balance which is very important to human life. Without heat there would be no planet Earth. Heat is important to keep our plants alive. When we were little, we learned that plants need water and sunlight to live. We also figured out that all of out vegetation dies in the winter because it cannot survive the cold.
Heat affects humans in the same way.
Two years ago many elderly were dying or being hospitalized for heat stroke during a hot streak in Chicago. The word heat is often used in our everyday language for different things. People often complain that their car is overheated in the summer. In the winter, people let their car heat up before driving. Heat is very important in cooking.