  Dissipative effects can lead to a friction term in the equation of motion for
an inflaton field during the inflationary era. The friction term may be linear
and localised, in which case it is described by a dissipation coefficient. The
dissipation coefficient is calculated here in a supersymmetric model with a two
stage decay process in which the inflaton decays into a thermal gas of light
particles through a heavy intermediate. At low temperatures, the dissipation
coefficient $\propto T^3$ in a thermal approximation. Results are also given
for a non-equilibrium anzatz. The dissipation coefficient is consistent with a
warm inflationary regime for moderate ($\sim 0.1$) values of the coupling
constants.
