  The kinetic Freeze Out process of a pion gas through a finite layer with
time-like normal is considered. The pion gas is described by a Boltzmann gas
with elastic collisions among the pions. Within this model, the impact of the
in-medium pion mass modification on the Freeze Out process is studied. A
marginal change of the Freeze Out variables temperature and flow velocity and
an insignificant modification of the frozen out particle distribution function
has been found.
