  The thermodynamics of 3d adjoint Higgs model is considered. We study the
properties of the Polyakov loop correlators and the critical behavior at the
deconfinement phase transition. Our main tool is a reduction to the 2d
sine-Gordon model. The Polyakov loops appear to be connected with the soliton
operators in it. The known exact results in the sine-Gordon theory allow us to
study in detail the temperature dependence of the string tension, as well as to
get some information about a nonperturbative dynamics in the confinement phase.
We also consider the symmetry restoration at high temperature which makes it
possible to construct the phase diagram of the model completely.
