  We describe how the coupling of the gluonic Polyakov loop to quarks solves
different inconsistencies in the standard treatment of chiral quark models at
finite temperature at the one quark loop level. Large gauge invariance is
incorporated and an effective theory of quarks and Polyakov loops as basic
degrees of freedom is generated. From this analysis we find a strong
suppression of finite temperature effects in hadronic observables below the
deconfinement phase transition triggered by approximate triality conservation
in a phase where chiral symmetry is spontaneously broken (Polyakov cooling). We
also propose a simple phenomenological model to describe the available lattice
data for the renormalized Polyakov loop in the deconfinement phase. Our
analysis shows that non perturbative contributions driven by dimension-2 gluon
condensates dominate the behaviour of the Polyakov loop in the regime T_c < T <
6T_c.
