No its normal, My snake hasn't been exposed to other animals, and we've and had no temp spikes. I mentions the water dish because my snake started to do it after it went into the water dish.
Have you checked your snake for mites? They will appear in the water bowl like little black specks of pepper. They would be located in the heat pits and near the eyes of your snake? Or have you treated the snake for mites at all?
Has he fed??? I wouldnt worry about it, just snakes being snakes but do check it for mites to be on the safe side...usually theyll spend alot of time soaking but i do have a couple of bps that just love to be in their water bowls for no reason and none have come up with mites. Good luck