  In this talk we review, the quasiparticle description of the hot Yang-Mills
theories, in which the quasiparticles propagate in (and interact with) a
background field related to Z(N)-lines. We compare the present description with
a more common one in which the effects of the Z(N)-lines are neglected. We show
that it is possible to take into account the nonperturbative effects at the
confinement transition temperature even without a divergent quasiparticle mass.
