Heat and Lighting

Reptiles are generally classified as 'ecto-thermic' or 'cold-blooded';  they actively control their body temperature by seeking out areas of warmth or moving away from them.

Building a thermal-gradient for basking reptiles can be thought of as simulated sun. For basking lizards like bearded dragons the sun is the source of heat and light. It controls day/night cycles (circadian rhythms), provides UV radiation that is both visible to reptiles(UVA) and necessary for proper health (UVB) and provides the thermal energy to power their bodies.

https://sites.google.com/site/thelizardmadness/enclosure-photos/truecolor.jpg
https://sites.google.com/site/thelizardmadness/enclosure-photos/thermal_gradient_may2015.jpg
Thermal Imaging helps illustrate the gradient, surface temperature readings are taken with a IR thermometer, and UVI readings taken with a Solarmeter 6.5.

T5 UVB lighting is quite strong and even a fixture 1/2 the width of the enclosure can provide a significant exposure through-out. This overlay is a very rough approximation. The original graph was made on a test bench, so does not align with 100% accuracy when superimposed on the photograph.

Light, heat and UV all come from the same source, the sun, in nature and should also in the vivarium. Positioning UV lights near the heat lights gives a 'photogradient' that allows the animal to seek out the "sun" for heat and retreat to "shade" when it needs to cool off.

Just light the sun, artificial light should come from overhead as well.
Aside from the UVB lights, special reptile branded lights are not needed, and typically do not provide any benefits beyond standard lights. I use halogen flood lights for basking lights.

The Basking Area should be large enough for the lizard to comfortably expose its entire body to a uniform warmth. An infrared thermometer is a very good tool to use to map out the basking area.

Ideally Pepper's tail would also fit on the platform,
however he can (and does) adjust his posture.


The thermal images below illustrate three different basking lights and the heat patterns projected on a slate tile. Some bulbs (in my experience outdoor glass lensed ones) even have visible bright spots that correspond to the hot spot on the tile.

Hot Spot
The light on the right is a 65W BR30 indoor Halogen.
The light on the Left is a 70W BR40. Both are mounted at 14" from the tile surface.


When I move the 65W BR30 bulb to 12" from the basking spot, and put the 70W BR40 bulb in the socket to the right of it I can make a large uniform warm area peaking at 113-115F. In a larger cage a variety of basking sites can be offered so the animal can select just how warm it wants to be.