  We present evidence for the existence of a quantum lower bound on the
Bekenstein-Hawking temperature of black holes. The suggested bound is supported
by a gedanken experiment in which a charged particle is dropped into a Kerr
black hole. It is proved that the temperature of the final Kerr-Newman
black-hole configuration is bounded from below by the relation
$T_{\text{BH}}\times r_{\text{H}}>(\hbar/r_{\text{H}})^2$, where $r_{\text{H}}$
is the horizon radius of the black hole.
