Hey guys. I just recently set up my ball python enclosure (plastic tub) and got my snake inside. Everything seems to be alright so far except for one thing.

I just received a temp gun in the mail to verify my temperatures read by my thermometer. Everything seems to be correct, but I had my thermometer probe on my hot side (reading 90 degrees) underneath my aspen bedding. On top of the aspen, which is around an inch or so, the measurements are in the low 80s. What can I do to make it hotter without risking burns to my snake if he burrows to the bottom?