Move the sub panel feeders to a breaker that is the right size for the wire and the main in the sub. It's possible the doubling up on the wires under the lugs have come loose. There should not be more than one conductor in each lug unless the lug is rated for two conductors. You have no overcurrent protection on the feeder. And if you don't have a main in the sub you could be in real trouble. That means no protection at all. Hot wires are the result of two things, overcurrent or loose connections. This should be addressed today.
