The hump or humps do not store water, since they are fat reservoirs. The ability to go long periods without drinking water, up to ten months if plenty of green vegetation and dew is available to feed on, results from a number of physiological adaptations of the animal. For example, camels can lose up to 40 percent of their body weight with no ill effects; they can also withstand a variation of their body temperature by as much as 14°F (8°C).