The modification of the width of the rho meson due to in-medium decays and
collisions is evaluated. In high temperature and/or high density hadronic
matter, the collision width is much larger than the one-loop decay width. The
large width of the ρ meson in matter seems to be consistent with some
current interpretations of the e+e− mass spectra measured at the CERN/SPS.Comment: 4 pages, LaTeX, including 4 Postscript figures, to appear in Proc. of
QM'99, Nucl. Phys.