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Article · Jun 7, 2026 · Citadel Culebra Faculty

The Thermal Gradient: Hot Side, Cool Side, and Why It Matters

A reptile regulates its body temperature by moving. If your enclosure is one temperature, you've taken that away.

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The Thermal Gradient: Hot Side, Cool Side, and Why It Matters
HusbandryAnatomy & PhysiologyBall PythonKenyan Sand BoaBeginner Basics

Reptiles are ectotherms — they run their entire metabolism on heat they borrow from the environment. A proper enclosure isn't 'warm,' it's a gradient: a hot zone they can move toward and a cool retreat they can move away to.

What this resource covers — basking surface vs. ambient, measuring with a temp gun and probes, why under-tank heat alone fails, thermostats, and species-by-species target ranges.

This is a free entry in the Citadel Culebra Library, expanded continuously by our faculty. The complete write-up is on the way — and members get every new entry first inside Culebra Connect.

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