  The Monte Carlo results in lattice QCD for the pressure and energy density at
small temperature $T < 155$ MeV and zero baryonic chemical potential are
analyzed within the hadron resonance gas model. Two extensions of the ideal
hadron resonance gas are considered: the excluded volume model which describes
a repulsion of hadrons at short distances and Hagedorn model with the
exponential mass spectrum. Considering both of these models one by one we do
not find the conclusive evidences in favor of any of them. The controversial
results appear because of rather different sensitivities of the pressure and
energy density to both excluded volume and Hagedorn mass spectrum effects. On
the other hand, we have found a clear evidence for a simultaneous presence of
both of them. They lead to rather essential contributions: suppression effects
for thermodynamical functions of the hadron resonance gas due to the excluded
volume effects and enhancement due to the Hagedorn mass spectrum.
