Is your snake digging in through the substrate and sleeping directly on the glass over the heat pad? I ask because, my temps were fine too, according to my thermometer and infrared gun, but mine kept coiling round and round until she was lying directly on the glass and managed to get a minor burn anyway. She's temporarily on newsprint while she heals, instead of the substrate I normally use, and she's now in shed, so her damaged scales should be better in short order - But just wanted to toss that out there, as I've had all kinds of worried nights over mine having belly skin problems all due to her heat pad, even though it was technically not "too hot".