Bearded dragons need a temperature gradient, not one temperature throughout the enclosure. They should be able to warm up under a basking area and move away to a cooler zone.
Bearded dragon basking temperature
A useful target for the basking surface is about 108–113°F. Measure the actual basking surface with an infrared temperature gun rather than relying only on air temperature.
Cool side temperature
The cool-side surface should generally stay around 77–85°F. This gives the dragon room to thermoregulate instead of being exposed to constant heat.
Night temperature
Bearded dragons benefit from a nighttime temperature drop. If your home becomes unusually cold, use an appropriate lightless heat source only when needed and control it with suitable temperature equipment.
Do I need a thermostat or temperature controller?
Temperature-control equipment is useful for secondary heat sources such as ceramic heat emitters and other lightless heaters. Always match the controller and fixture to the heat source and manufacturer instructions.
Browse Bearded Dragon Supplies for basking, UVB and heating equipment, and read What Fixture Do I Need for a Ceramic Heat Emitter? if you are adding supplemental heat.