Use paper towels, reoccurrence solved. That snake is dehydrated and having a bad shed. I would get rid of the dirt and put a wet dish towel in the enclosure as substrate over night. Sopping wet with clean warm water. Put the water dish over the hot spot as well. I would remove it in the morning and replace with clean dry paper towels then put a small wet rag over the warm spot in one corner. See if the snake can get the substrate out on its own.