The study of chemical phenomena occurring above 500 K (440°F). High temperatures represent one of the important variables available to scientists for increasing the variety of possible chemical reactions over that expected for classical ground-state atoms and molecules. One can enhance the relative population of excited rotational, vibrational, and electronic states by increasing the temperature and thus effectively create new species and new mechanisms for reaction. The potentialities of this approach are well illustrated by the three laws of high-temperature chemistry: (1) At high temperatures everything reacts with everything. (2) The higher the temperature, the faster the reaction. (3) The products may be anything. With an infinity of species available at high temperatures, the “golden age” of chemical synthesis is probably still in the future.