How Do We Obtain Heat?
We get most of our heat from the sun. If the heat from the sun did not reach us, no living thing would exist on the earth. No plants or animals could live; the oceans and rivers would be solid ice.
Another important source of heat, is chemical action. Chemical action is what causes fire. Even when it does not cause fire, it produces a great deal of heat. When we breathe to keep our bodies warm, it is a chemical action that occurs. Fire is the most important form of chemical action, as a source of heat.