Reptiles are exothermic—they regulate their body temperature by moving around in their environment. Some reptiles bask in the sun, while others spend time sitting on rocks warmed by the sun after it's sunk below the horizon.
In order to keep our scaly pets healthy in captivity, we need to provide a proper temperature gradient, and in a form that mirrors their natural behaviors. Remember, regardless of how you're providing heat to your pets, monitoring the temperature is a necessity. We strongly recommend the use of an infrared thermometer or digital thermometer.
There are multiple ways to provide heat to your reptiles. For the sake of this article, we've divided them into two basic categories:
Heat rocks pose a danger to your pets if they malfunction and shouldn't be used. Heat pads and heat tape should be used with a Rheostat or thermostat as a backup to ensure the device does not overheat. Leopard geckos, invertebrates, and most snakes will thrive with belly heat.
Heat pads are ideal for glass enclosures, where they can be attached (with foil tape or a self-adhesive side) to the bottom or side glass. Most are designed to run at a set temperature, which will vary by brand.
Heat tape is best utilized for a rack or sweater box system, and can be run below or behind tubs. This material is useful for breeders, as it allows economical, even heating for a large number of animals off of one thermostat and plug.
Basking lights replicate thermal energy from the sun and provide radiant heat from above. They are great for diurnal basking animals, such as bearded dragons, iguanas, day geckos, and the like. In general, the higher the wattage, the hotter the bulb and basking spot.
Daylight bulbs provide a hot spot and a clean, white light. They are great for providing a higher temperature basking spot during the day, but should not be utilized over night.
Red bulbs, Night Basking Bulbs (typically a purplish-blue color), and Ceramic Heat Emitters can be used 24/7 to provide heat. The first two emit light at a wavelength that will not bother nocturnal animals or keep diurnal animals awake. Ceramic Heat Emitters produce heat, but no light.
All basking lights produce heat—most do not produce UVA or UVB in significant amounts. One exception are Mercury Vapor Bulbs. Although they are more expensive (generally $30-$60 each), they can provide all the heat and UV your animal needs for up to a year.
Each species of reptile has a recommended basking or hot spot temperature, as well as a minimum daytime temperature. This allows them to thermoregulate - move back and forth between different temperature zones in the enclosure in order to maintain their ideal body temperature.
You can learn a lot about a setup based on how the animal behaves, for example, let's look at a bearded dragon.
If that bearded dragon stays away from the basking spot the entire day, the basking spot (and possibly the entire enclosure) is too warm. Provide a lower wattage basking spot or increase the ventilation of the enclosure.
If the bearded dragon stays glued to the spot underneath the basking bulb, the bulb is too cold. Increase the wattage of the bulb to ensure a basking spot of 105-115F.
If the bearded dragon basks for 5-15 minutes at a time, then moves about the enclosure, temps are probably spot on.