You can also use a lamp dimmer as a thermostat but you do have to pay attention more closely then with a regular thermostat. Lamp dimmer lowers the watts in heating device and will maintain that wattage even in change of room temperature. So say your room is 70 and your hotspot is 90 but tomorrow your room is 85 then your hot spot will be much higher, same if the room got colder then the hotspot will be colder. But with a proportional thermostat it will raise and lower the wattage of your heat device to keep it perfect temperature. I'm constantly checking temps so lamp dimmer is ok for me. I will be upgrading to herpstat soon though. I would recommend you get a proportional thermostat bc they will maintain constant temp for the most part. The on/off style will fluctuate, it will turn on device when at 85 and shut off at 91, just like a home furnace, which I would think could be stressful to an animal. Whether you choose a lamp dimmer or thermostat you will need to monitor your temps, never rely on something that keeps your bp healthy electrical devices can fail at anytime.