Hmm I have the XL exo terra reptile cave which I'm getting rid of as soon as my two Medium hides from RBI arrive...
I have the same exo terra hide in my 24" high cage with an RHP, and inside it's cooler than the surrounding floor.
This new cage is only 15" high, so maybe that will make a difference...
I have a question for you... do you measure the temperature on top of the hide with the same device and the temp inside the hide? My tstat probe gives a different reading than my temp gun so that's what I measure all my temps with.