  We study $D$ and $D_s$ mesons at finite temperature using an effective field
theory based on chiral and heavy-quark spin-flavor symmetries within the
imaginary-time formalism. Interactions with the light degrees of freedom are
unitarized via a Bethe-Salpeter approach, and the $D$ and $D_s$ self-energies
are calculated self-consistently. We generate dynamically the $D^*_0(2300)$ and
$D_s(2317)$ states, and study their possible identification as the chiral
partners of the $D$ and $D_s$ ground states, respectively. We show the
evolution of their masses and decay widths as functions of temperature, and
provide an analysis of the chiral-symmetry restoration in the heavy-flavor
sector below the transition temperature. In particular, we analyse the very
special case of the $D$-meson, for which the chiral partner is associated to
the double-pole structure of the $D^*_0(2300)$.
