  I discuss the masses of chiral partners in the context of chiral symmetry
restoration at finite temperature. Using the Nambu-Jona-Lasinio model I first
remind the usual situation where two mesons of opposed parity become degenerate
above the chiral transition temperature. Then I consider an effective theory
for D mesons where the positive parity companion presents a "double pole
structure". In this case three different masses need to be analyzed as
functions of the temperature. I suggest a possible restoration pattern at high
temperatures when the back-reaction of the quark condensate is incorporated.
