  The presence of a substantial number of hot stars in the extremely
metal-rich} open cluster NGC6791 has been a mystery. If these hot stars are in
their core helium burning phase, they are significantly bluer (hotter) than
predicted by canonical stellar evolution theory. No obvious explanation is
available yet. We consider the effects of mass loss during the evolution of
horizontal branch (HB) stars as their possible origin. We find that the
addition of mass loss causes HB stars to evolve to be hotter and fainter. Mass
loss has a more pronounced effect for less massive stars and thus naturally
widens the temperature (and color) distribution on the HB. If mass loss rates
are higher for more metal-rich stars, this phenomenon would be even more
pronounced in the metal-rich populations, such as NGC6791. We find that mass
loss on the HB may be a viable method of forming subdwarf B (sdB) stars both in
the field and in clusters, especially when the metallicity is high.
