First thing is: do you have the UTH on a thermostat? If not, unplug it. No heat source should go unregulated. A UTH that is not regulated can cause serious burns. What exactly are you using for substrate? The substrate will have lower temps than plastic or ceramic hides. The temps you should be concerned about it where the hides are. A hot spot can range from 90 to 95 really but 92 is ideal.

Yes, your new buddy will decide to move between hot and cold sides on his own.