Crested geckos are ectotherms, commonly referred to as “cold-blooded.” This biological classification means they are completely reliant on external heat sources to manage their internal body temperature. Unlike mammals, they lack the internal physiological mechanisms necessary to generate their own warmth and maintain a constant core temperature. This reliance on the environment dictates nearly every aspect of a crested gecko’s care and habitat design.
The Science of Ectothermy
The biological term for “cold-blooded” is ectothermy, meaning “outside heat.” Ectotherms absorb heat from their surroundings, such as warm air or heated surfaces, which directly influences their metabolic rate. This contrasts with endothermy, found in birds and mammals, where the organism generates its own body heat internally through metabolic processes.
The term “cold-blooded” is misleading because an ectotherm’s body temperature simply matches the ambient environment; it is not necessarily cold. This difference in thermoregulation results in significantly lower metabolic rates compared to endotherms of a similar size. Since they do not burn vast amounts of energy maintaining a constant body temperature, ectotherms require substantially less food to survive.
Habitat Requirements for Temperature Control
The ectothermic nature of the crested gecko requires the enclosure to provide a precise thermal range for proper health and digestion. The ideal daytime range is typically between 72 and 78 degrees Fahrenheit (22 to 25.5 degrees Celsius). Nighttime temperatures can safely drop slightly lower, usually between 69 and 74 degrees Fahrenheit (20.5 to 23 degrees Celsius).
Temperatures consistently exceeding 85 degrees Fahrenheit (29 degrees Celsius) are dangerous and can quickly cause severe stress or death. Due to this sensitivity, supplementary heating equipment like heat lamps is often unnecessary and hazardous for this species. If a heat source is required to maintain the minimum range, a low-wattage ceramic heat emitter or a deep heat projector connected to a thermostat is the safest option.
A minor temperature gradient must be created within the enclosure, even if the overall range is small. This allows the gecko to move to a slightly warmer or cooler spot to regulate its body temperature behaviorally. Owners should monitor both the warm and cool zones using a reliable digital thermometer to ensure the entire habitat remains within safe parameters.
Recognizing and Preventing Thermal Stress
Because crested geckos cannot self-regulate their temperature, they are vulnerable to thermal stress. Consistent temperatures above the safe zone can rapidly lead to heat stroke and neurological issues. Signs of overheating include lethargy, becoming limp, or hiding exclusively on the cool, damp substrate. A gecko may also exhibit “gaping,” or opening its mouth, as an attempt to cool down through evaporative cooling.
If a gecko shows signs of being too hot, move the enclosure to a cooler room or lower the ambient temperature using a fan or air conditioning. Misting the gecko and the enclosure more frequently can provide temporary relief through hydration and surface cooling. Conversely, if temperatures are too low (below 72 degrees Fahrenheit), the gecko may become sluggish, refuse food, and exhibit poor balance, signaling chronic hypothermia. For a cold gecko, gradually raising the temperature back into the ideal range using a low-wattage heat source is the correct intervention.