  We discuss the critical properties of the three-dimensional NJL model at
nonzero temperature. We show that the Z(2)-symmetric model undergoes a second
order phase transition with 2d Ising exponents and its critical region is
suppressed by a factor 1/N^{-0.5}. We also provide numerical evidence that the
U(1)-symmetric model undergoes a BKT transition in accordance with the
dimensional reduction scenario.
