I am curious as well, how exactly do you measure his temps? You say you have digital thermometers, but are they on the substrate? Under it? A few inches up the side? A few degrees can make a big difference. What may be barely noticeable to us can be very uncomfortable for your snake. The digital thermometers with a probe on a wire are the ones most keepers like the best. Because the probe can be placed wherever it's needed to get an accurate reading.

Just because he's hiding, it's no need for concern, but incorrect temps are a major problem. I know, I went through it myself.

Try to get a thermostat as soon as you can, because even a little tiny UTH can burn your baby.

Gale