A summary is given of different elementary processes influencing the thermal balance and energetic conditions of substrate surfaces during plasma processing. The discussed mechanisms include heat radiation, kinetic and potential energy of charged particles and neutrals as well as enthalpy of involved chemical surface reactions. The energy and momentum of particles originating from the plasma or electrodes, respectively, influence via energy flux density (energetic aspect) and substrate temperature (thermal aspect) the surface properties of the treated substrates. The various contributions to the energy balance are given in a modular mathematical framework form and examples for an estimation of heat fluxes and numerical values of relevant coefficients for energy transfer, etc. are given. For a few examples as titanium film deposition by hollow cathode arc evaporation, silicon etching in CF4 glow discharge, plasma cleaning of contaminated metal surfaces, and magnetron sputtering of aluminum the energetic balance of substrates during plasma processing will be presented. Furthermore, the influence of the resulting substrate temperature on characteristic quantities as etching or deposition rates, layer density, microstructure, etc. will be illustrated for some examples, too.