Ultraviolet light is needed for the lizard to properly synthesize vitamin D. In the wild, UVB rays are naturally provided by the sun, and in a captive environment, is needed to prevent the lizard from developing any calcium deficiency (Metabolic Bone Disease). Also, dust the lizard's prey with a calcium supplement specifically for reptiles as indicated by the manufacturer. Purchase an appropriate heat lamp and UVB bulb for your reptile. Keep a thermometer in the terrarium to monitor the temperature. The mid to upper 70s (23 - 26 Celsius) is fine and in the upper section of the enclosure, near the heat lamp, the temperature can range from the lower to mid 80s (27 - 30 Celsius).