Green Functions in Coordinate Space for Gauge Bosons at Finite   Temperature
  The thermal Green function $D^{\mu\nu}(x)$ for free, massless gauge bosons is computed exactly in a variety of gauges (Feynman, covariant, Coulomb, and Landshoff-Rebhan). At large temporal separations it falls exponentially. At large spatial separations it falls like $T/r$. In contrast, the zero-temperature propagator falls quadratically in both regimes, being proportional to $1/x^{2}$. 
H. Arthur Weldon