Polycarbonate is routinely subjected to heat treatment, and the thermal degradation products formed during this thermal treatment give rise to a distinct structured fluorescence spectrum. The structured fluorescence emission is observed when polycarbonate is subjected to thermal treatment in air as well as in nitrogen. A mixture of thermal rearrangement products of polycarbonate including dibenzofuran and phenyl-2-phenoxybenzoate are mainly responsible for the structured fluorescence emission. Most of the thermal degradation products of polycarbonate undergo photolysis, leading to the formation of photoproducts, which subsequently undergo a photoinduced bleaching process, with the noted exception of phenyl-2-phenoxybenzoate. The exposure of polycarbonate to high temperature for only short time periods, simulating mild industrial processing conditions, results in the formation of a relatively small amount of thermal degradation products, which, accordingly, has only a minor effect on the photodegradation of polycarbonate.