  We compute the finite temperature pole mass shifts of the octet and decuplet
baryons using heavy baryon chiral perturbation theory and the 1/N_c expansion,
where N_c is the number of QCD colors. We consider temperatures of the order of
the pion mass m_\pi, and truncate the chiral and 1/N_c expansions assuming that
m_\pi \sim 1/N_c. There are three scales in the problem: the temperature T, the
pion mass m_\pi, and the octet--decuplet mass difference. Therefore, the result
is not simply a power series in T. We find that the nucleon and \Delta
temperature mass shifts are opposite in sign, and that their mass difference
changes by 20% in the temperature range 90 MeV < T < 130 MeV, that is the range
where the freeze out in relativistic heavy ion collisions is expected to occur.
We argue that our results are insensitive to the neglect of 1/N_c- supressed
effects; the main purpose of the 1/N_c expansion in this work is to justify our
treatment of the decuplet states.
