A black hole has a thermodynamic temperature:
Black holes are usually fed by an accretion disk of superheated gas and plasma. As this plasma swirls around at near the speed of light, it acts as a massive dynamo, generating incredibly powerful magnetic fields. The spinning black hole itself can drag space-time around with it (frame-dragging), twisting these magnetic field lines into tight, powerful coils that shoot massive jets of radiation across the universe.
Because the empty space of the universe is warmed by the Cosmic Microwave Background (CMB) to 2.7 Kelvin, all black holes are currently absorbing far more energy from space than they are radiating away. Their native quantum temperature is entirely masked by the universe's background warmth.
