  We use three-flavor chiral perturbation theory ($\chi$PT) to calculate the
pressure, light and $s$-quark condensates of QCD in the confined phase at
finite temperature to ${\cal O}(p^6)$ in the low-energy expansion. We also
include electromagnetic effects to order $e^2$, where the electromagnetic
coupling $e$ counts as order $p$. Our results for the pressure and the
condensates suggest that $\chi$PT converges very well for temperatures up to
approximately 150 MeV. We combine $\chi$PT and the Hadron Resonance Gas (HRG)
model by adding heavier baryons and mesons. Our results are compared with
lattice simulations an d the agreement is very good for temperatures below
{170} MeV, in contrast to the results from $\chi$PT which agree with the
lattice only up to $T\approx120$ MeV. Our value for the chiral crossover
temperature is 160.1 MeV, which compares favorably to the lattice result of
$157.3$ MeV.
