  Earlier attempts to extract parameters of kinetic freeze-out in Pb+Pb
collisions at 158$A$GeV are critically reviewed. Many of these analyses have
used approximations which have significant impact on the extracted parameters.
Simple estimates are obtained which attempt to avoid the most critical
approximations. It is pointed out that constraints based on pion interferometry
are less reliable than those from momentum spectra. A universal set of
freeze-out parameters from transverse mass spectra would require T > 135 MeV
and <beta> < 0.35.
