ESDU 89022 defines quantities and gives equations required in estimating the temperature of a structure due to aerodynamic heating. The terms are specific heat capacity, thermal conductivity, thermal diffusivity, emissivity, absorptivity, heat transfer coefficient, Biot number, stagnation temperature, and recovery temperature and factor. The equation is given for the equilibrium skin temperature under aerodynamic heating allowing for radiation heating both to and from the structure, and its applicability to thin skins in which no temperature gradient exists is considered. The case of thick skins is also considered, and methods of determining the temperature distribution under various simplifying assumptions are discussed.