  We studied screening masses in the equilibrium thermodynamics of SU(2) and
SU(3) pure gauge theories on the lattice. At a temperature of 2 Tc we found
strong evidence for dimensional reduction in the non-perturbative spectrum of
screening masses. Mass ratios in the high temperature SU(3) theory are
consistent with those in the pure gauge theory in three dimensions. At the
first order SU(3) phase transition we report the first measurement of the true
scalar screening mass.
