We analyze the spontaneous U(1)R symmetry breaking at finite temperature
for the simple O'Raifeartaigh-type model introduced in [1] in connection with
spontaneous supersymmetry breaking. We calculate the finite temperature
effective potential (free energy) to one loop order and study the thermal
evolution of the model. We find that the R-symmetry breaking occurs through a
second order phase transition. Its associated meta-stable supersymmetry
breaking vacuum is thermodynamically favored at high temperatures and the model
remains trapped in this state by a potential barrier, as the temperature lowers
all the way until T=0.Comment: 19 pages, 4 figures - Minor revisions, references added. To appear in
JHE