Thermoregulation in reptiles is the process by which these animals maintain and control their body temperature. Unlike mammals and birds, reptiles are ectothermic, meaning they rely on external heat sources to regulate their internal temperature. This balance is achieved mainly through behavioral adaptations, such as basking in the sun to absorb heat or seeking shade to avoid overheating. Understanding thermoregulation is crucial to appreciating how reptiles thrive in various environments and maintain optimal physiological function.