NUCLEONS AT FINITE-TEMPERATURE

The nucleon mass shift is calculated using chiral counting arguments a nd a virial expansion, without and with the Delta. At all temperatures , the mass shift and damping rate are dominated by the h. Our results are compared with the empirical analysis of Leutwyler and Smilga, as w ell as results from heavy baryon chiral perturbation theory in the lar ge N-c (number of color) limit. We show that unitarity implies that th e concepts of thermal shifts are process dependent.