Heat & Light

Bearded dragons are diurnal — active during the day, resting at night. During the day, they require a strong overhead heat source that replicates solar radiation. At night, no supplemental heat is required in most Australian climates unless the temperature drops below 5°C.

Heat must come from above. Bearded dragons are built to absorb radiant heat from above, as they would from the sun. Heat mats, heat cables, and under-tank heaters do not replicate this and can cause burns, stress, and thermoregulation failure.

Halogen bulbs or other bright, natural-spectrum globes are preferred for daytime basking. Avoid coloured or red bulbs. Ceramic heat emitters do not provide the light component of basking and are not suitable as the primary daytime basking heat source.

All heat sources must be controlled by a thermostat without exception. The Inkbird ITC-306T is recommended for reliability and ease of use. The thermostat probe must be positioned at the cool end, not at the basking zone.

The shape and positioning of the basking structure matter just as much as the temperature itself. Tapered natural logs positioned beneath the heat source and UVB provide a far more functional basking gradient than flat rocks or tiles.

Always use an infrared temperature gun to measure surface temperatures. Stick-on thermometers and dial gauges are not accurate enough for this purpose and should not be used as a primary measurement tool.

The basking surface temperature should sit between 42–45°C, and may briefly peak near 50°C directly under the basking zone during the hottest part of the day. This is measured on the surface of the basking structure directly under the heat source, using an infrared temperature gun.

The cool end should sit at approximately 28°C or below. This temperature allows the dragon to move away from the heat source and cool down as needed. Without a functional cool end, the dragon cannot thermoregulate.

Temperature is controlled primarily by the height of the basking structure relative to the heat source. Raising the structure increases surface temperature; lowering it decreases it. The wattage of the bulb and the thermostat setting also affect the result.

Bearded dragons follow a natural biphasic activity pattern — basking in the morning to reach operating temperature, moving to cooler areas midday, and returning to the basking zone in the afternoon. A correctly set up enclosure will allow this to happen without intervention.

Healthy Central Bearded Dragons generally do not require supplemental heating overnight unless the enclosure temperature falls below approximately 5°C. Around Whyalla, winter temperatures can fall into the low single digits, and dragons have been observed emerging to bask after mornings of approximately 3–4°C once sunlight and radiant heat become available. This natural comparison supports allowing a normal overnight temperature drop, but captive dragons should not be deliberately exposed to extreme cold. Very young, unwell, underweight or medically compromised dragons may require different management. Below approximately 5°C, a low-wattage ceramic heat emitter controlled by a thermostat can be used. Heat mats must not be used.

Bearded dragons are adapted to intensely bright, open environments. Bright visible light supports activity, feeding response, and natural behaviour. UVB is an inseparable part of that — it enables the production of Vitamin D3, which is required for calcium absorption. Without adequate UVB, calcium cannot be processed correctly regardless of supplementation. The result, over time, is metabolic bone disease.

UVB output cannot be seen by the human eye. A bulb can appear bright and functional while producing no usable UVB. This is why tubes must be replaced every 12 months, even if they still appear to be working.

Fusion’s standard is a reputable T5 High Output UVB tube rated at 10% or 12%, mounted inside the enclosure rather than above mesh or glass. It must overlap the basking zone and extend from the hot end across approximately half to two-thirds of the enclosure. The percentage printed on the tube does not, by itself, determine how much UVB reaches the dragon. The lamp model, reflector, mounting distance, obstructions and age of the tube all affect the resulting exposure. Follow Fusion’s approved positioning for the selected equipment and replace the tube every 12 months unless its output is being reliably measured with an appropriate UV meter.

UVB output degrades over time even when the tube still appears to be lit. Fusion’s standard is to replace the tube every 12 months unless its output is being reliably measured with an appropriate UV meter.

Use a timer to maintain a consistent daily lighting schedule. Standard months: 12 hours on, 12 hours off. During summer, up to 14 hours on is appropriate. Consistency in the light cycle supports natural behaviour and appetite.

Adult Bearded Dragons generally handle brumation far better than rapidly growing juveniles. Younger dragons are still developing and require consistent feeding, strong UVB exposure, and proper basking opportunities to support healthy growth. Realistically, if you’ve purchased your dragon from a reputable breeder, it will often be around 4–6 months old by the time seasonal slowdowns commonly begin around April and May. At this age, a few quiet days up to around two weeks can be normal, however prolonged inactivity should not simply be ignored. Encouraging them back under the basking area each morning can help maintain proper digestion, activity levels, and continued development. If the dragon is younger than 4 months old, it is generally recommended to encourage daily basking and maintain slightly warmer enclosure temperatures if necessary, particularly on the cool end. While some juveniles may show mild seasonal slowdowns, prolonged brumation in very young dragons is generally not ideal and should be monitored carefully.