What term describes heat waves that are self-timed and self-heated?

The term that describes heat waves that are self-timed and self-heated is exothermic. In the context of chemical reactions, an exothermic process is one where energy is released in the form of heat. This release of heat can lead to an increase in temperature in the surrounding environment, which is characteristic of self-heating events.

In the context of perms and relaxers, understanding exothermic reactions is crucial. For example, many of the chemical processes involved in hair treatments can generate heat as a byproduct, which helps to activate other chemicals or enhance the efficacy of the treatment. This is why exothermic reactions can be vital in achieving the desired results in hair treatments.

The other terms, while related to heat and reactions, do not capture the idea of a self-timed and self-heated phenomenon in the same way. Endothermic refers to processes that absorb heat rather than release it. Chemical is a broad term that encompasses all types of reactions but does not specifically address the heat aspect. Thermal generally refers to heat but lacks the specificity regarding the self-heating and timing characteristics that exothermic provides.