The Importance of Heat
For all reptiles, providing appropriate temperatures is extremely important. Being ectothermic ("cold-blooded" - although they need warm temperatures) they rely on external temperatures to regulate their body temperature. In the wild, they naturally gravitate to an area with the temperature they need, moving into the sun or into shaded areas as necessary. Therefore, a temperature gradient must be provided so that the reptile can choose the appropriate temperature as needed.
Obviously, temperatures must not be so high as to overheat the reptile. Just as important, however, is that temperatures not be too low since processes like digestion are only efficient at the right body temperature. At temperatures that are too low, a reptile may become sluggish and unable to digest its food properly.
For the reasons mentioned above, a gradient must be provided. Typically a basking light or other heat source can be placed at one end of the tank so that the temperature there is at the high end of the range for the reptile species. The other end should be maintained around the lower temperature range for the species. More on setting up a gradient can be found in How to Set Up a Thermal Gradient.
However, providing the gradient isn't quite that simple. Depending on what sort of reptile you are housing, accessories should be placed in the tank in such a way that the reptile can use the gradient while behaving naturally. So, if your reptile likes to hide, some kind of shelter or hide should be provided in both the warm and the cool ends, so the reptile isn't tempted to hide all day in a shelter that is not at the optimum temperature. Similarly, if your reptile is arboreal, the appropriate temperatures must be avaialble up in the branches that the reptile climbs on; the reptile can then themoregulate and still be in its preferred location.
This may sound like a lot of trouble, but the key is to provide conditions that mimic what the reptile would find in its natural environment. Invest in a couple of good thermometers and regularly monitor the temperatures in different areas of the cage (especially where your reptile is spending a lot of time) and make sure the temperatures are correct. Remember the proper temperature is vital to your reptile's health!
Many captive reptiles do fine with a slight temperature drop at night (that is what many experience in the wild). Many reptile care sheets recommend a night time or minimum temperature. A slight gradient can still be provided, again to let the reptile choose where it wants to be.
There are several options for providing heat and the best one(s) for you will depend on your reptile and your enclosure. Overhead heating more naturally replicates a reptile basking in the sun, but under tank heating is a good option to supplement the heat provided. If at all possible, avoid heat sources placed within the cage, or at least make sure they are shielded to prevent direct contact between the reptile and the heat source to prevent burns. This is particularly important for some species (e.g. iguanas). Hot rocks should generally be avoided - often they can be hot enough to burn a reptile that rests on one, yet they do not do much for heating the whole tank. And of course, make sure all heating devices are used in an appropriate and safe manner to reduce the risk of burns or fires. A few options are presented below.
- Basking lights, spotlights, incandescent lamps - these represent a simple and effective way to provide heat as well as day time light. They come in a variety of wattages and some experimentation may be necessary to find the right combination of distance and power to provide the right temperature. White bulbs can't be used 24 hours a day, though (your reptile needs some time in the dark too), so a dim colored bulb can be used at night. Night time bulbs made specifically for reptiles are a good choice. This type of heat is a nice choice since it provides a baking spot for your pet.
Ceramic heating elements - these screw into a socket much light a bulb, but do not emit any light. They produce a lot of heat and must be used only in a ceramic socket rated for the element or there is a risk of overheating and fire.
Under tank heating pads and tape - human heating pads are okay but not ideal. Special heat pads and heat tape can be purchased for reptiles. These under tank heat sources are a good choice for supplementing heat provided by a basking light, or providing heat at night.