Reptiles self-regulate their body temperature by basking in warm areas and cooling down in other areas of the habitat. Maintaining the proper terrarium temperature is critical for proper digestion, growth, nesting and overall everyday activity. If too cool, reptiles may become sluggish and go off food. If too warm, the pet will spend more time trying to find a cooling spot and slowly overheat. Zilla Heat Mats and Heat Emitters are two ways to provide required warmth to a terrarium.