A mathematical model is presented which describes the heating effect of short 1.06 mu m laser pulses absorbed by interband and intraband transitions in silicon. The model is based on recent experimental investigations of these absorption processes. It shows that the heating depends on the free carrier absorption to a large extent. The model allows for the temperature dependence of the absorption parameters, and predicts that a pulse energy of 2 J cm^-2 is required to melt the surface of a silicon crystal that is initially at room temperature. This value is consistent with experiments reported in the literature.