By "temperature gradient", it means having a cool side and a warm side to an enclosure. Reptiles are cold blooded and they need to be able to regulate their own temperature.

By providing a "cool" side of 80-84 degrees and a "warm" side of 90-94 degrees (with an identical hide on each side), your BP would be able to thermoregulate (regulate his body temperature) by moving between hides to keep his internal temps "right".

I hope that makes sense? With BP's length/width of enclosures are WAY more important than the height of the enclosures--and the height might be freaking him out, in addition to not really having the gradient to thermoregulate.