  Chiral thermodynamics of charmed mesons is formulated at finite temperature
within a $2+1+1$-flavored effective Lagrangian incorporating heavy quark
symmetry. The chiral mass splittings are shown to be less sensitive to the
light-quark flavors, attributed to the underlying heavy quark symmetry.
Consequently, chiral symmetry restoration is more accelerated in the strange
charmed-mesons than in the strange light mesons, and this is in striking
contrast to the chiral SU(4) result. We also show the correlations between
light and heavy flavors around the chiral crossover.
