Do Crested Geckos Need Heat and UVB?

"Crested geckos need no heat lamp and no UVB" is real beginner appeal, and mostly true. But "mostly" is doing work here, and this guide — the deep-dive companion to our Crested Gecko Enclosure Setup Guide — exists because the honest answer turns on a number you probably haven't measured: your own room's temperature.

Do Crested Geckos Need a Heat Lamp?

The Short Answer, and the Condition Attached to It

In most homes, no. Bean Farm — a commercial crested gecko breeder and retailer — states plainly that crested geckos thrive at 72–78°F with no special heating equipment, matching common household settings, and can safely drop to 65°F at night Bean Farm. That's a defensible part of the low-equipment pitch, for a lot of keepers — but it doesn't extend to a heat mat or coloured night bulb. ReptiFiles is explicit: skip black, blue or red bulbs for night viewing or heat — crested gecko eyes function fine in the dark, and night light disrupts the day/night rhythm the species relies on. A nightly drop is healthier than night heat, not a problem to fix ReptiFiles.

The Temperature Numbers, Side by Side

Three sources, three slightly different framings, worth seeing side by side.

The Ceiling: Why Overheating Is the Fastest Way to Kill a Crested Gecko

What Happens Above 85°F

Consistent temperatures above 85°F can cause stress and heat stroke ReptiFiles. Reptiles Reptropolis corroborates: at 85°F or warmer, crested geckos become stressed, which can lead to illness or death Reptiles Reptropolis. Bean Farm sets the alarm lower — stress above 80°F, prolonged exposure above 82°F potentially fatal Bean Farm. A genuine disagreement: ReptiFiles treats 82–85°F as a target basking range, and Bean Farm calls part of that same range potentially fatal.

The distinction that resolves it, and one almost no competitor draws clearly: a small, localised, thermostat-capped warm zone the gecko can walk away from is not the same risk as whole-enclosure ambient temperature. The dispute above is about whether that localised zone is beneficial or merely tolerable — but a heatwave death is an ambient-temperature death, not a warm-zone death. Keep ~85°F as the hard ceiling for the enclosure as a whole. Weighing this against a far more heat-dependent species that needs a real basking hot spot just to digest? Our Crested Gecko vs. Leopard Gecko comparison covers that difference.

The Three Overheating Scenarios That Actually Happen

How to Cool an Enclosure Instead of Heating It

If your home runs hot in summer, cool the enclosure rather than heating it: move it to a cooler room, run a small fan nearby without blowing directly on it, or lean on AC during a genuine heatwave Bean Farm.

The Floor: The Case That "Room Temperature" Advice Goes Too Far

What the Evidence Says About Cool-Side Lethargy and Appetite Loss

ReptiFiles states that many people claim room temperature with no heat source is fine — but in her experience, lack of access to a heat source is the most common cause of the lethargy, poor appetite and illness she sees in crested geckos, and that temperatures at or below 72°F can themselves cause exactly those problems ReptiFiles. Her remedy: a low-wattage white or clear bulb, starting around 25W in a small hood or 50W in a 5.5" dome, adjusted from there ReptiFiles. Independent corroboration: Arcadia states its ShadeDweller, ProT5 and JungleDawn LED Bar products should be provided alongside a thermostat-controlled heat source Arcadia Reptile.

Why Ectotherm Digestion Is the Mechanism

The reasoning is physiological, not anecdotal: crested geckos are ectotherms, unable to generate their own body heat, relying on environmental heat to regulate metabolism and digest food ReptiFiles. A gecko in a genuinely cool room isn't just uncomfortable — its digestion is running at the wrong temperature. Worth remembering if your gecko goes off food for no obvious reason; our Crested Gecko Not Eating and Losing Weight guide covers that troubleshooting path, temperature included.

Where the Disagreement Actually Lies

Bean Farm's counter-position, stated fairly: supplemental heating is conditional — "if your home is consistently cooler than 72°F, you can provide gentle supplemental heating" — with high temperatures the greater concern Bean Farm. Line the positions up and the dispute narrows: everyone agrees on the ceiling, and that no hot basking lamp is needed. The real questions are whether a warm top zone is beneficial or merely tolerable, and whether a 68–72°F room is genuinely fine or, per ReptiFiles' clinical experience, the commonest cause of the appetite problems keepers report.

If You Do Need Heat: How to Add It Safely

Low-Wattage Overhead Heat, Not Heat Mats or Coloured Bulbs

If your room genuinely runs cool, the fix is overhead, low-wattage, white or clear light — not a heat mat underneath and not a coloured "night" bulb ReptiFiles. A low-wattage halogen flood is the simplest version; Arcadia's low-watt Deep Heat Projector is the no-visible-light alternative Arcadia Reptile.

Thermostats Are Not Optional

Any added heat source needs a thermostat — Arcadia pairs its lighting with a thermostat-controlled heat source, not an unregulated one Arcadia Reptile. An Inkbird is a workable, budget starting point; a Herpstat proportional unit is the premium option a basic on/off model can't match.

Hatchlings and Grow-Out Enclosures Are a Special Case

Hatchlings under roughly 13 grams are a different problem. ReptiFiles notes they're often housed in small grow-out enclosures with no room on top for a bulb — so the correct approach is a small heat pad on one side, on a proportional thermostat, probe between pad and wall, capped at 85°F/29°C, off at night ReptiFiles. The one context here where a heat mat is the right answer, since there's no usable overhead space yet.

How to Measure Temperature Properly

Probe Thermometer vs. Temperature Gun

A digital probe thermometer, placed in the basking or warm area, gives a continuous reading. ReptiFiles says to avoid cheap ribbon thermometers common in pet stores — inaccurate, and a failure here risks cooking the gecko ReptiFiles.

An infrared gun gives instant surface readings anywhere in the enclosure, recommended for checking the gradient ReptiFiles.

Where to Measure (Top, Bottom, and Why Both)

One reading can't tell you whether you have a gradient or a uniformly warm box. Measure top, bottom, and ambient room, and log all three. Temperature and humidity are managed together in practice — the same gradient thinking applies to the wet/dry cycle covered in our Crested Gecko Humidity and Misting Setup guide.

Do Crested Geckos Need UVB?

The Traditional Answer and Why It's Changing

ReptiFiles notes many people say UVB isn't necessary since a quality prepared diet supplies D3, and a lack of UVB won't necessarily kill a crested gecko — but she cites a growing body of evidence that UVB substantially increases health and quality of life for reptiles previously thought not to need it, and recommends it for all reptiles, crested geckos included ReptiFiles. UVB bulbs also emit UVA, a spectrum reptiles can see and humans can't — Arcadia frames it as "activated colour vision" ReptiFiles; Arcadia Reptile.

A veterinary framing adds the mechanism: like all lizards, crested geckos need UVB to synthesise D3 in the skin for calcium metabolism and MBD prevention, and UVB exposure improves immune function and supports circadian rhythms Catherine Love, DVM — Arbor View Animal Hospital — though part of that is extrapolated from leopard gecko studies, not crested-gecko-specific data, a caveat most competitor pages skip. Exo Terra, a manufacturer with an obvious commercial interest, adds that research on crested geckos, leopard geckos and corn snakes shows a positive UVB/D3-synthesis correlation Exo Terra. Honest bottom line: "beneficial, low-output, optional" is the defensible position — not "required."

Ferguson Zone 1 and the UVI Target

Crested geckos are crepuscular, typically hiding behind leaves by day, placing them in Ferguson Zone 1 — the lowest-exposure category. ReptiFiles targets a UV index of 1.0–2.0 at the basking branch, measured with a Solarmeter 6.5 ReptiFiles. Our own hub pillar states a more conservative in-house 0.6–1.0 — both worth knowing, and either way, verify with a meter.

Which Lamp, at What Distance

ReptiFiles' figures assume the lamp sits above mesh with roughly 35% block; Arcadia's own figures for the same 7% lamp run slightly closer, in free air ReptiFiles; Arcadia Reptile. Differently conditioned, not contradictory — mesh type and free-air-vs-over-mesh both change the answer:

The Arcadia ShadeDweller ProT5 kit bundles the 8W 12"/30cm fitting, lamp, fittings kit, power cable and a link cable for up to ten kits on one power source; the 7% lamp runs 7% UVB/17% UVA, and both ShadeDweller lamps carry a 12-month lamp life Arcadia Reptile — a recurring cost, not a one-time buy. A Zoo Med ReptiSun 5.0 T5 is the accessible alternative; for hatchlings, ReptiFiles recommends a 13W ReptiSun 5.0 compact in a 5.5" dome on a stand instead ReptiFiles.

The Glass-and-Plastic Mistake That Wastes a UVB Bulb

Glass and plastic both block UVB entirely, rendering an otherwise correct bulb useless ReptiFiles — a common mistake almost no competing page mentions.

Lighting Even Without UVB: Photoperiod Matters

Per Baines' UV-Tool, crested geckos should get roughly 14 hours of light daily in summer and 10 in winter, with gradual transitions — supporting circadian rhythm, seasonal cycling, activity and appetite Baines et al., Journal of Zoo and Aquarium Research; ReptiFiles. Even a keeper skipping UVB entirely should run this cycle on a timer — almost no competitor page says so. In a planted enclosure, that same question extends to the plants; our Crested Gecko Bioactive and Planted Setup guide covers plant-grade lighting like the JungleDawn LED Bar.

If You Skip UVB, Your Supplement Routine Changes

Complete Diet Alone: No Supplementation Needed

Pangea's own guidance: its diets are formulated with calcium and D3 at levels for healthy growth and bone development, and geckos not laying eggs — including males and juveniles — shouldn't need extra calcium added to the food Pangea Reptile.

The Moment You Offer Insects, Dusting Becomes Mandatory

The instant insects enter the picture, that answer flips. Pangea is explicit: if you offer insects, it's still necessary to lightly dust them with a calcium and D3 supplement, recommended for geckos kept without UVB Pangea Reptile. The mechanism is the inverted calcium-to-phosphorus ratio in feeder insects, working against the ratio a complete diet is built to hit. Not a hedge — not optional.

With UVB vs. Without UVB — Which Powder

UVB changes which dust you use, not whether you dust. With adequate UVB, the gecko synthesises its own active vitamin D and won't need D3 supplementation — a multivitamin alongside good UVB should be D3-free. Without UVB, use calcium with D3 Catherine Love, DVM — Arbor View Animal Hospital.

Why Over-Supplementing Is Its Own Risk

Don't add supplement powder to prepared complete diet, with one exception: egg-laying females, where Pangea says a little plain calcium in the food, or in a separate dish, is safe and sometimes necessary Pangea Reptile. Complete diets are formulated for a specific mineral balance, including oxalate levels calibrated to support calcium absorption, and dusting on top disrupts that.

Over-supplementation is a real risk, not a hedge — too much can cause harm, particularly with fat-soluble vitamins like D SpectrumCare, citing VCA and Merck Veterinary Manual. "They don't need supplementation" fails exactly like "they don't need heat" — true of the default case, false once a condition changes: a cricket, or a cold room.

Putting It Together: Three Household Scenarios

1. Room sits 72–78°F year-round, complete-diet-only, no UVB. The majority reader: a thermometer and hygrometer, plus a photoperiod timer. No added heat, no supplements.
2. Room drops below 72°F in winter, or the gecko is sluggish and off food. Add low-wattage overhead heat at the top, on a thermostat, capped well below 85°F, off at night.
3. Room exceeds 82–85°F in summer, or the enclosure catches direct sun. The emergency case: cool the room, move it out of the sun, add no heat at all. Dust insects only if the diet includes them.

The equipment here is modest next to a basking desert species, but it adds up — especially a UVB bulb on a 12-month cycle. Our Crested Gecko Setup Cost and Shopping List breaks down what it costs.