If the room is at 90 just unplug the heat and just use ambient I do it all the time with various species.
If that was my snakes I would pre-treat for mites whether needed or not and make sure to keep the animal cool by making sure cold water is in the bowl at all time and having a fan circulating the air in the room.
A vet is not likely to find anything, it's you as the owner that need to investigate and keep an eye on the animal, because no one know YOUR animal better than YOU.