  The temperature dependence of the liquid-drop fission barrier is considered,
the critical temperature for the liquid-gas phase transition in nuclear matter
being a parameter. Experimental and calculated data on the fission probability
are compared for highly excited $^{188}$Os. The calculations have been made in
the framework of the statistical model. It is concluded that the critical
temperature for the nuclear liquid--gas phase transition is higher than 16 MeV.
