What is the temperature inside a Black Hole? Is it insanely hot? Cause of so much gravity?
Is it close to absolute zero? Cause the matter is so closely packed, there is hardly any space for particles to move?
Is it room temperature? Cause Cooper didn't die in Interstellar when he went into a Black Hole?
The temperature of a black hole as seen from the outside is the temperature of the Hawking radiation, which @jyoti has discussed.

The temperature you would experience as you fell freely through the event horizon, is a different question. I think the answer depends on what else is falling into the black hole at the same time. From its own viewpoint, everything that falls into a black hole reaches the singularity in a fixed maximum time (a few days for the very largest supermassive black holes) so you could only exchange energy with things that fell in around the same time as you did. If there was very little such stuff, then I don't think you'd notice anything out of the ordinary -- you'd be exposed to the cold of space, just as you were before (assuming the black hole is big enough that you haven't been heated up the tides of the black hole distorting you. On the other hand if lots of stuff was falling into the black hole with you then the whole lot would get churned up, and you'd be falling in as part of a mass of very hot plasma. Eventually, at least in a non-spinning black hole, you'd approach the singularity and be ripped apart by tides.