The thermodynamics of four-dimensional SU(2) $$ \mathcal{N} $$ =2 super-Yang-Mills theory is examined in both high and low temperature regimes. At low temperatures, compelling evidence is found for two distinct equilibrium states related by a spontaneously broken discrete R-symmetry. These equilibrium states exist because the quantum moduli space of the theory has two singular points where extra massless states appear. At high temperature, a unique R-symmetry-preserving equilibrium state is found. Discrepancies with previous results in the literature are explained.