When we confine reptiles in captivity, we must provide a cool area and a warm area so that the animal can determine its own body temperate as it would in the wild. At night the temperature can safely drop to 70-75 degrees, provided that the animal can warm up during the day. The best way to provide a basking site is to use a basking lamp. A branch should be placed laterally under the heat lamp to provide the animal with a basking site. Make sure to screen in the bulb or place the bulb out of the iguana's reach so it cannot burn itself.
Proper heating is important to maintain a healthy immune system and proper digestion.
It should be noted that heating rocks are not appropriate heat sources for iguanas. Arboreal reptiles do not lay their bellies against hot surfaces in the wild to warm up, and should not be forced to do so in captivity. Full spectrum lighting simulates the wavelengths of natural sunlight. Iguanas need this vitamin in order to absorb calcium in their diets. Without full spectrum lighting, iguanas develop a condition called metabolic bone disease, which is a calcium deficiency.