Reptiles are ectotherms that rely entirely on external temperature sources to regulate body function. Providing appropriate thermal gradients is the most critical welfare requirement for captive reptiles.
Temperature is not simply a comfort factor for reptiles - it determines whether their immune system functions, whether they can digest food, and whether they can reproduce. A reptile kept too cold is chronically immunosuppressed and in a state equivalent to systemic illness. Yet many keepers underestimate the importance of a true thermal gradient across the full length of the enclosure. The investment in appropriate thermostats, multiple heat sources and accurate thermometers directly determines the quality of life of the animal in your care.