Always provide a heat source that is not also a light source in order to provide the correct period of darkness whilst maintaining the vivarium temperature. Secondary heat source - specific areas can be provided with a higher temperature. For lizards, a 50 - 75W bulb directed downwards is generally adequate. A heat pad is used to maintain ambient temperature. Polystyrene should be fixed to the back of the heatpad, and under the base of a glass vivarium.
Monitoring is important to check range of temperatures.
The ambient temp should not exceed the PBT, the temp under hot spot should not exceed the maximum tolerated. Maximum and minimum thermometers and thermostats are essential. Timers are required for the maintenance of a stable photoperiod. It should be obvious from the above that it is not suitable to have the ambient heat source as a light source, or the reptile will be stressed. Must be replaced every 6 months to ensure effectiveness.