Endothermy is the ability of an organism to regulate its body temperature internally, maintaining a stable temperature regardless of external conditions. This adaptation allows endothermic animals, such as mammals and birds, to thrive in various environments, from cold polar regions to hot deserts. Endothermic organisms generate heat through metabolic processes, which helps them remain active and energetic. Unlike ectothermic animals, which rely on external heat sources, endotherms can sustain their body temperature even in fluctuating climates, giving them an advantage in survival and activity levels.