The advice here is to use hides that just fits the BP, so that it's touching on all sides. OK, easy enough to do. HOWEVAH...

During the first month we had our little BP, we used the tree hide that came with it (the one at both Petco and Petsmart). It gives a LOT of space around it, especially vertical space inside. Since we didn't have another hide, it stayed inside that tree hide over the warm spot, and we had no problems.

Very soon after I bought a set of plastic bowls and cut doorways out to use as warm and cool hides, our BP went through a week or so of daytime cruising and constantly pushing upward, trying to escape. (That also coincided with our holding it more than before, so I don't know how much each is a factor.) It also didn't even go into the warm hide for days.

Rabernet here came to the rescue, and ever since filling the base of the tank with crumpled up newspaper, Patriot has stayed in the warm hide; only once in the cool. The door of the hide is now covered by newspaper, so he's now more hidden inside.

If the hide is to be a snug fit, cutting a door into it exposes the BP, and in my case, exposed it too much. How to you find a happy middle ground? With the tree hide, a snake has space inside to move away from the door and not be exposed. Even though there is a window on the other side from the door, it's an inch off the bottom, so that inch below is just another wall like the rest of it.