You may have to play around with it to find the right setting. You want to ensure the hottest part your BP can reach (ie. the bottom of the cage right above the heat pad) to never get above 95 degrees. 92 degrees for that hot part would be fine. I think my thermostat probe, sandwiched between the heat pad and the outside bottom of the enclosure, was set at 95-96 degrees to keep things 91 degrees on the inside floor. You may also have to reduce the thickness of the substrate, but this will have the added benefit of letting more heat radiate up from the UTH.