  Large-N phase transitions occurring in massive N=2 theories can be probed by
Wilson loops in large antisymmetric representations. The logarithm of the
Wilson loop is effectively described by the free energy of a Fermi distribution
and exhibits second-order phase transitions (discontinuities in the second
derivatives) as the size of representation varies. We illustrate the general
features of antisymmetric Wilson loops on a number of examples where the phase
transitions are known to occur: N=2 SQCD with various mass arrangements and
N=2* theory. As a byproduct we solve planar N=2 SQCD with three independent
mass parameters. This model has two effective mass scales and undergoes two
phase transitions.
