  Technical concepts are presented that improve the selfconsistent treatment of
vector-mesons in a hot and dense medium. First applications concern an
interacting gas of pions and rho mesons. As an extension of earlier studies we
thereby include RPA-type vertex corrections and further use dispersion
relations in order to calculate the real part of the vector-meson selfenergy.
An improved projection method preserves the four transversality of the
vector-meson polarisation tensor throughout the selfconsistent calculations,
thereby keeping the scheme void of kinematical singularities.
