At very high temperatures and constant heat loads even camels need to dissipate heat. Many mammals achieve evaporative cooling through an increased respiratory rate rather than by sweating. Respiratory cooling is relatively more expensive in water than is sweating since faster respiration rates result in more energy being used. Normal respiratory rates in camels are in the range of 6 to 11 breaths/min. (average 8) in the Sahara. Under heat stress these increase to levels of 8 to 18 (average 16). Such low respiration rates do not result in significantly increased evaporation. .
