  Right since its discovery in 2003 by the Belle collaboration, establishing
the nature of the $X(3872)$ meson has been one of the main priorities in the
field of quarkonium physics. Not qualifying as a conventional $c\bar{c}$ state,
the multiquark structure of this exotic meson has received very different
interpretations, ranging from a compact tetraquark configuration to an extended
$D\bar D^*+c.c.$ molecule. In this work we explore the effect that a hot pion
bath may have in the properties of the $X(3872)$, assuming this state to be a
$D\bar D^*+c.c.$ molecule. We derive the finite temperature effects on the
$X(3872)$ from a coupled channels unitarized amplitude, obtained including the
properties of the charmed mesons under such conditions. We find that the
$X(3872)$ develops a subtantial width, of the order of a few tens of MeV, in
hot pionic environments at temperatures $100-150$ MeV, and its nominal mass
moves above the $D D^*$ threshold. The fact that the $X(3872)$ in a hot pion
gas may no longer be a narrow resonance needs to be considered in the
estimation of production yields in relativistic heavy-ion collisions.
