A picture would definitely help.
Also remember when dealing with heat sources such as a radiant heat panel, ceramic heat emitter, deep heat projector, etc. that the relationship between the intensity of the radiation and the distance from the heat source isn't linear, it's quadratic. So an object two feet from a heat source will only get one quarter of the intensity as an object one foot from it. This is why you don't want a surface under the RHP to go over the low 90's; if your snake lies on it, its back can get a lot hotter than that.
A solid/dense hide such as the wooden half-log will act as thermal mass; it will absorb a lot of heat, hold it, and radiate it slowly over time which is probably why your snake likes being under there.