Until recently hot cores were the first indirect manifestation of a young massive star, but recent observational successes are now providing us with the first candidates for the very early phases of massive star formation, probably the precursors of hot cores. The characteristic hot core chemistry is believed to arise from the evaporation of the icy mantles that accumulate on the dust grains during the collapse the leads to the formation of the massive star. The duration over which the grains are warmed is determined by the time taken for a pre-stellar core to evolve to the Main Sequence. Hence, hot cores and their precursors contain an integrated record of the physics and chemistry occurring during the collapse that led to the star. In this article I will review recent advances in the chemical modelling of hot cores and their precursors in light of the recent TPD experiments on a variety of ices and I will briefly discuss the implications of such studies for the interpretation of high mass protostellar objects.