Okay, remember that our body temperature is roughly 98.6* so that "cage" would need to be over 98.6* to feel warm to you, which actually COULD be warm enough to cause skin damage, especially to a BP that's already on the thin & frail side if he made prolonged contact there. This may be part of the issue- why the damaged skin was also very dry.
If that was my snake, I'd be putting some sort of soothing antibiotic/antiseptic ointment on that very open wound until you can get him seen by a vet. Best option is Vetericyn brand ointment -make sure it's the version FOR reptile use, because it's water-based & won't cause the skin issues (bad sheds after much use) that petroleum-based ointments* can. (*ie. Triple-antibiotic or Neosporin). Or if you can get your hands on some, Silvadene cream is best to use (a Rx may be required). It's made for humans but is generally safe for snake use, & I have used it in a similar situation- lots of it, & as suggested by my vet att. I did not use any sort of bandages, as they could cause more trouble than they'd be worth (ie. more damage). The Silvadene cream was re-applied often to the open wounds, with the snake kept on clean paper towels & minimal set-up (nothing for the snake to be further injured by- no branches or anything like that).
https://www.webmd.com/drugs/2/drug-4...opical/details
generic name for Silvadene: Silver sulfadiazine Medicinal
Silver sulfadiazine, sold under the brand Silvadene among others, is a topical antibiotic used in partial thickness and full thickness burns to prevent infection. Wikipedia