all of my thermostat probes are connected to my UTH on the outside of the cage. I place a probed thermometer right where the snake is going to be inside the hide then adjust the thermostat up til it reaches the desired temp on the thermometer. So that will be your number! example 93 deg. on your thermostat really = 90 deg in the cage to compensate for cage material , substrate, etc. from there you can raise or lower accordingly. Your heat loss transfer rate should stay the same.