  We consider the Casimir-Helmholtz free energy at nonzero temperature $T$ for
a circular cylinder and perfectly conducting wedge closed by a cylindrical arc,
either perfectly conducting or isorefractive. The energy expression at nonzero
temperature may be regularized to obtain a finite value, except for a singular
corner term in the case of the wedge which is present also at zero temperature.
Assuming the medium in the interior of the cylinder or wedge be nondispersive
with refractive index $n$, the temperature dependence enters only through the
non-dimensional parameter $2\pi naT$, $a$ being the radius of the cylinder or
cylindrical arc. We show explicitly that the known zero temperature result is
regained in the limit $aT\to 0$ and that previously derived high temperature
asymptotics for the cylindrical shell are reproduced exactly.
