pvc heating issues (again)

[Bogertophis]

because of the thickness of the pvc i can’t attach it underneath. however, would attaching the UTH to a piece of glass so he’s not on it directly and then shoving it inside the cage be an option?

A better option might be to looking into the heat pads sold for canine whelping quarters & farm animals (aka "pig blanket"), since they're made sealed & safe for moisture & outdoor use. Then you could have it right inside the enclosure, instead of trying to get heat thru a thick enclosure bottom.

This is one kind I located quickly & it comes in 3 sizes: (I used to have & use a couple similar ones made for dogs that were insulated hard plastic, but same idea.)
https://www.chewy.com/kh-pet-product...tdoor/dp/46435