[Tris]

Given that the thermal energy of the black hole would be associated with matter, and the matter of a black hole is contained within the event horizon any radiation would be contained within the event horizon.

The thermal emissions I learnt were associated with black holes are those from acceleration effects on matter. For instance a star/black hole orbitting each other, with the hole pulling matter from the star, which then spirals around the black hole until it dissapears into it. Radiating quite a lot as it does.