In nature heat is transferred through radiation and conduction.
In captivity, the goal is to simulate radiant and conductive sources. In most instances, you will have to do this by providing supplemental heat through man-made and natural options to aid in your reptile’s digestion.
Radiant Heat
Radiation is the transfer of heat through space in the form of waves. This type of heat comes from above (top-down), similar to how the sun warms the air and environment with radiant energy.
In captivity, it’s important to ensure reptiles cannot come into direct contact with heat or light sources. Always use proper fixtures—such as a secured light bracket—instead of placing bulbs directly on top of the enclosure screen.
Incandescent Bulbs
Most bulbs are incandescent.
They have a filament.
They provide omnidirectional heat (coming from all directions).
Majority of incandescent bulbs cannot produce adequate UVA/UVB, except for mercury vapour bulbs.
Spotlight Bulbs
Spotlights provide direct heat to a basking area.
They are identified by the frosted edge around the bulb which provides directional heat.
These bulbs are great for creating a basking spot in a smaller enclosure.
Ceramic Emitter
Ceramic emitters do not produce light, making them great for heating a tank at night.
Must use a wire fixture (regular fixture is a fire hazard because there is not enough air flow).
Infrared Bulbs
Like ceramic emitterss, these bulbs are great for nighttime heating. Many reptiles are unbothered by red light, allowing them to rest if they are diurnal (awake during the day), or display regular behaviours if they are noctural (awake at night). Think of it as a nightlight, as the reptile may still see the glow but not enough to impact their behaviours.
They typically provide omnidirectional heat (coming from all directions).
Halogen Bulbs
Day = white/blue, Night = red.
These bulbs are an economical option because they last longer and are more energy efficient.
There are low profile options available.
Conductive Heat
Conduction is the transfer of heat through direct contact or touch.
This type of heat comes from below (bottom-up). A radiant heat source—such as the sun or a heat bulb—warms a surface like a rock or substrate, which then retains and releases that heat to your reptile when they come into contact with it.
Natural Sources
Natural sources like branches, rocks, or the forest floor act as heat-conductors and are heated by the sun. A radiant heat source can also create a conductive one, just like the sun.
Placing dense rocks in a reptile’s habitat will create natural conductive heat sources, as the rock will remain warm after the heat source is shut off.
Artificial Sources
(Under Tank Heaters/Heat Pads)
Heating pads placed under the enclosure will conduct heat through 1 1/2 inches of sand or 2-4 inches of other reptile bedding.
If using with aspen bedding, place a layer of reptile carpet on the bottom of the enclosure to minimize direct contact with the hot flass for prolonged periods of time.
Food and water dishes should not be placed above the Under Tank Heater.
Heat pads should be used with infrared or probe thermometers as the surface will be warmer than the air. They can only be stuck on a surface once, and go on the outside of the tank.
Creating a Temperature Gradient
Reptiles require a carefully controlled environment to avoid temperature extremes. As ectotherms, they rely entirely on their surroundings to regulate their body temperature.
It’s important to teach guests how to create a proper temperature gradient within the enclosure. Reptiles depend on us to recreate a natural, balanced habitat that allows them to thermoregulate effectively.
There should always be a warm side and a hot (basking) area—never a true “cold” side. Temperatures that are too low can lead to health issues, including respiratory problems.
If a reptile consistently stays on one side of the enclosure, it’s a sign the temperature gradient may need to be adjusted.
Thermostat
To regulate the temperatures in the enclosure and ensure control in case of a malfunction, a thermostat is an important tool!
The thermostat accurately controls terrarium temperatures by turning your existing heat source on when temperatures are too low, and off when they reach the target.
Exoterra 300W thermostat controls terrarium temperatures from 20°C-35°C (68°F-95°F) and turns on/off.
Thermometer
Provide at least two reptile thermometers to monitor either side of the enclosure. Set one at the hottest place and one at the coolest to measure the gradient.
Guests need to know that fish thermometers do not measure temperatures high enough for many reptile enclosures.
Stick-on thermometers are inexpensive, but difficult to read and less accurate.
Dial thermometers are more accurate, but still needs to be replaced fairly often.
Digital thermometers are the most accurate. Only one needs to be purchased because it can be moved throughout the tank to monitor the gradient.
