  The conventional results for hard thermal loops, which are the building
blocks of resummed perturbation theory in thermal field theories, have
collinear singularities when external momenta are light-like. It is shown that
by taking into account asymptotic thermal masses these singularities are
removed. The thus improved hard thermal loops can be summarized by compact
gauge-invariant effective actions, generalizing the ones found by Taylor and
Wong, and by Braaten and Pisarski.
