Do crested geckos need UVB and heat?

The cool-temperate framing

Crested geckos (Correlophus ciliatus) evolved in the cool moist forests of New Caledonia — naturally low temperatures, dense foliage, never extremely hot. Per the PetMD crested gecko care sheet and the ReptiFiles crested gecko care guide, their husbandry differs dramatically from desert geckos and basking lizards:

• No basking spot needed — they don't bask in the wild and don't need a hot spot in captivity.
• Cool ambient temperatures — 72–78 °F / 22–26 °C target.
• Heat is dangerous — sustained over 80 °F / 27 °C is lethal.
• Most rooms provide enough heat naturally without supplemental bulbs.

The framing isn't "warm enough" but "not too hot." Heat stress is the single largest preventable cause of crested gecko deaths.

Temperature targets

Most household rooms in temperate climates naturally sit in the 72–78 °F window without active heating or cooling. The cresty's husbandry decision is usually less about adding heat and more about preventing heat — keeping the room cool enough in summer.

When supplemental heat is needed

Only in cool rooms (consistently below 65 °F / 18 °C ambient). Options:

• Deep heat projector (DHP) at low wattage on a thermostat set to 72–75 °F. Best option — naturalistic heat profile, no visible light.
• Low-wattage ceramic heat emitter (CHE) on a thermostat set similarly.
• Heated room (raise central heating) — often simpler than enclosure-specific heating.

Never:

• Heat mat under enclosure — crested geckos are arboreal and don't benefit from ground heat.
• Basking bulb — creates a hot spot the gecko doesn't need.
• Any heating without thermostat — risk of overheating.

Heat stress is the real risk

The Zen Habitats crested gecko Q&A and most modern care guidance identify heat stress as one of the single biggest preventable causes of crested gecko death. Symptoms:

• Gaping — mouth held open for extended periods.
• Lethargy outside normal day-rest pattern.
• Refusal to eat.
• Drooping posture, weak grip on branches.
• Floor-firing tail syndrome (FTS) — caudal autotomy from stress.
• Drinking from water bowl unusually often.

If you observe any of these in a warm room, cool the enclosure immediately. Sustained heat stress can be fatal within days.

Cooling a hot enclosure

When room temperatures hit 80 °F+:

1. Move enclosure away from windows, heat sources, direct sun.
2. Place a fan to move air across the enclosure (not blowing directly on the gecko).
3. Freeze water bottles and place near (not in) the enclosure. The cool surface lowers ambient.
4. Run AC to keep room under 80 °F.
5. Cooled water-filled humid hide (small container with cool damp moss) for a cool retreat.
6. Lighter misting more often — drops temperature via evaporation.
7. Reduce lighting — even non-heat-emitting LEDs add slight warmth in small enclosures.

Plan ahead for summer. A crested gecko keeper in a non-AC home in a hot climate needs a cooling strategy before the first warm week.

The UVB question

Historically, crested geckos were kept without UVB on the basis of their nocturnal habits and the success of calcium-with-D3 supplementation. The modern consensus has shifted, mirroring the leopard gecko UVB shift over the past decade.

Current recommendation: low-level UVB (UVI 0.5–1.0 from a T5 HO 5.0 tube) is now best practice, though crested geckos can be kept on supplementation alone.

The case for UVB:

• Safety margin against missed dustings or aged supplements.
• More natural D3 synthesis than dietary D3 alone.
• Reduced supplementation cadence needed — calcium-with-D3 1–2×/week instead of every insect feeding.
• Modern care guides increasingly recommend it.

The case against (still valid for established setups):

• Crested geckos are crepuscular shade-dwellers — minimal wild UV exposure.
• Decades of CGD-only keeping produced healthy long-lived geckos.
• Cost and complexity of adding lighting to an enclosure that didn't need it.

Picking the right UVB

If you choose to add UVB:

Glass blocks ~95 % of UVB — mount inside the enclosure, not on top of glass. Cover only one-third to one-half of the enclosure top to create a UVI gradient.

Supplementation with vs without UVB

Don't dust the CGD regardless of whether you use UVB. CGD already contains balanced calcium with D3 and vitamins; additional calcium causes hypervitaminosis.

What about visible light?

Crested geckos need a photoperiod (12 hours day / 12 hours night) for circadian rhythm even without basking. Options:

• Ambient room light during the day — often enough on its own if windows are nearby.
• Low-wattage LED above the enclosure during the day.
• UVB tube (if used) — provides some visible light.

Never use white light at night. Crested geckos are crepuscular — most active at dusk and dawn — and need a true dark phase for healthy sleep. See reptile night temperatures.

A complete simple setup

For a crested gecko in a normal-temperature household:

1. Enclosure at 72–78 °F ambient — verify with a digital thermometer.
2. No basking bulb.
3. Optional T5 HO 5.0 UVB tube mounted above branches on a 12-hour timer.
4. Optional low-wattage LED for visible day light.
5. No supplemental heat unless room drops below 65 °F.
6. Cooling plan for summer (fan, AC, frozen bottle nearby).
7. CGD as staple (see crested gecko diet).

Setup cost: under $100 for the temperature/lighting portion. Most of the budget goes to enclosure, foliage, branches, and misting system.

The summary framing

Crested geckos need cool ambient temperatures (72–78 °F), no basking spot, and protection from heat above 80 °F. Low-level UVB is modern best practice but not strictly required. Most rooms provide adequate warmth without supplemental heat. Get the temperature side right and the gecko lives a long quiet life.

For the broader care plan, see crested gecko care guide. For enclosure setup, see crested gecko enclosure setup. For the cross-species UVB framework, see cross-species UVB guide.