  We study the temperature evolution of the rho and sigma mass and width, using
a unitary chiral approach. The one-loop pion-pion scattering amplitude in
Chiral Perturbation Theory at finite temperature is unitarized via the Inverse
Amplitude Method. Our results predict a clear increase with T of both the rho
and sigma widths. The masses decrease slightly for high T, while the
rho-pion-pion coupling increases. The rho behavior seems to be favored by
experimental results. In the sigma case, it signals chiral symmetry
restoration.
