  We compare recent lattice studies of QCD thermodynamics at non-zero quark
chemical potential with the thermodynamics of a hadron resonance gas. We argue
that for T < Tc the equation of state derived from Monte--Carlo simulations of
two flavour QCD at non-zero chemical potential can be well described by a
hadron resonance gas when using the same set of approximations as used in
current lattice calculations. We estimate the importance of truncation errors
arising from the use of a Taylor expansion in terms of the quark chemical
potential and examine the influence of unphysically large quark masses on the
equation of state and the critical conditions for deconfinement.

High Energy Physics - Phenomenology;High Energy Physics - Lattice;Nuclear Theory