Here's why:
* Mammals are endotherms: Rhinos belong to the class Mammalia, and all mammals are endothermic. This means they have a stable internal body temperature regardless of the external environment.
* Maintaining a stable body temperature: They do this through metabolic processes that generate heat, and by regulating their heat loss through mechanisms like sweating, panting, and insulation from fur or fat.
While some animals may be able to tolerate some fluctuations in their body temperature, endothermic animals like the black rhino have a much narrower range, keeping it relatively constant.