Considering a glass cage setup with coconut husk substrate and a UTH:

There are 3 temperatures you can monitor.. the ambient air temperature, and the substrate temperature at both sides of the cage(cool and warm)

If you are using a thermostat, which temperature should it be regulating? Or do thermostats regulate multiple temperatures somehow?

Also, do UTHs really provide enough heat to get the ambient air temperature up to the low 80s?