Their large size allows them to absorb more heat. They use less water for evaporative heat loss during the day and, at night, rely on conduction and radiation to lose the heat gained in the day. They must be physiologically capable of tolerating such body temperature extremes. Thick fur with high insulation value that retards heat gain. Shorn camels use more water.
Camels can tolerate a greater water loss than most mammals.
Exhaled air cooled by long, narrow nasal passages. Don't stand broadside to the sun when they can avoid it. Most of the water enters through their gills or other breathing surface. Aquatic mammals and birds are mostly impervious to osmotic loss or gain of water over their body surface, but marine organisms have to drink water and excrete sodium.