  An detailed study of the thermodynamical state of nuclear matter in transport
calculations of heavy--ion reactions is presented. In particular we determine
temperatures from an analysis of the local momentum space distribution on one
hand, and from a fit to fragment energy spectra in terms of a blast model with
radial flow and temperature on the other. We apply this to spectator and
participant matter. In spectator we find regions of spinodal instability with
temperatures and densities which are consistent with experiments. In the
participant we find different temperatures for different fragment masses,
indicating that the fragments are not emitted from a source in thermal and
chemical equilibrium.
