A proportion of the heat added to a body of rock during prograde metamorphism will be absorbed in the chemical work of metamorphic recrystallization. When and where heat is so absorbed will affect the exact thermal histories of the rocks, and hence the metamorphic textures. This paper reports the results of modelling of the inter-relations between reaction progress and thermal histories in a rock column. The results suggest that volumes of rock undergoing reaction at any moment act as heat sinks and absorb heat from the surrounding rock, that reaction generally takes place close to the temperature at which nucleation took place, and that steady heating of a rock pile can give rise to a reaction history in which spurts of reaction are separated by ‘quiet’, non-reactive intervals.