My floor in the bathroom is very hot just picked up a towel and felt the heat on the towel then felt the floor.I have done nothing it is not visible just need to know what this is?

Assuming you have a concrete floor, you most likely have a leaking hot water pipe under the floor.

I would also have to assume they don't have a heated floor and do not know about it ?

Sure sounds like you have a hidden leak in your hot water line. To check to see if you have a hidden leak first shut down everything in the house, no flush, no drinks of water, and if you are on a meter go out and check the little pointer in the gage. It should not move or creep. If it does you have a leak.N If you're on a pump then check the pressure gage after the pump builds up to pressure and shuts off. The gage should not fall and the pump come back on. If so then you have a leak. Hope this helps and thank you for rating my reply, Tom