Camels can travel up to 161 km (100 miles) in the hot desert without water. But contrary to popular misconception, a camel’s hump is not filled with water. Instead, it is filled with fat (up to 36 kg, or 80 lbs.) that is metabolized for energy and water when needed.
As the fat is used up, the hump will become flabby, so if you see a camel with a flabby hump — or no hump at all — feed it, because it is probably very hungry.
The Haus of Dcaligari 