Fire is a chemical reaction. In a chemical reaction, molecules (themselves composed of a set of atoms) are rearranged in new molecules by creating and/or removing bound between atoms. Creating/removing these bounds will either release or absorb some amount of energy. When the reaction release energy, it is an exothermic reaction. When it absorb energy it is an endothermic reaction. Fire is the energy released by some exothermic reactions, in the form of heat and light.

deleted by creator

We decided to call what fire does to us “hot” and what ice does to us as “cold”. They are physically both different manifestations of the same thing, temperature.