<P> Camels are able to withstand changes in body temperature and water consumption that would kill most other animals . Their temperature ranges from 34 ° C (93 ° F) at dawn and steadily increases to 40 ° C (104 ° F) by sunset, before they cool off at night again . In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day (Breulmann, et al., 2007) Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a rete mirabile, a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain . Camels rarely sweat, even when ambient temperatures reach 49 ° C (120 ° F). Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat . Camels can withstand losing 25% of their body weight to sweating, whereas most other mammals can withstand only about 12--14% dehydration before cardiac failure results from circulatory disturbance . </P> <P> When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water . Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking . </P> <P> The camels' thick coats insulate them from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating . During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn . The camel's long legs help by keeping its body farther from the ground, which can heat up to 70 ° C (158 ° F). Dromedaries have a pad of thick tissue over the sternum called the pedestal . When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body . </P> <P> Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants . Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand . If sand gets lodged in their eyes, they can dislodge it using their transparent third eyelid . The camels' gait and widened feet help them move without sinking into the sand . </P>

What were camels used for in the middle east