  We investigate the effect of the medium on the thermal conductivity of a pion
gas out of chemical equilibrium by solving the relativistic transport equation
in the Chapman-Enskog and relaxation time approximations. Using an effective
model for the pi-pi cross-section involving rho and sigma meson exchange,
medium effects are incorporated through thermal one-loop self-energies. The
temperature dependence of the thermal conductivity is observed to be
significantly affected.
