It is very important that the temperature and humidity of your enclosure is kept at an adequate level. Iguanas for example, require a preferred optimal temperature range (POTR) of 75-88 degrees F. With an optimal basking range of 88-95 degrees F. It is a good idea to provide your reptile several different temperature points to rest. This can be accomplished with shelves, decorative branches, vines, and other cage accessories.
Recommendation: Use a ceramic heat emitter to provide a 24 heat source without creating disruptive light at night. Then use a spot lamp to provide a basking spot and a fluorescent fixture with a full spectrum bulb for daytime lighting.