A camel's hump does not store water, a common misconception; it stores fat, which the animal draws on for energy when food is scarce and which, broken down, releases some water as a byproduct but not nearly enough to explain the animal's famous endurance without water. The real trick lies elsewhere: camels can tolerate a body temperature swing of several degrees over the course of a day, avoiding the energy cost of sweating to stay at a single fixed temperature the way most mammals do. Kidneys that produce highly concentrated urine and the ability to lose a large fraction of body water without dying complete the picture.