  Electromagnetic emission rates from a thermalized hadronic gas are important
for the interpretation of dilepton signals from heavy-ion collisions. Although
there is a consensus in the literature about rates for a pure meson gas,
qualitative differences appear with a finite baryon density. We show this to be
essentially due to the way in which the pi-N background is treated in regards
to the nucleon resonances. Using a background constrained by unitarity and
broken chiral symmetry, it is emphasized that the thermalized hadronic gas can
be considered dilute.
