Sheep farming is an important social and economic support for the population living in semi-arid zones. These climatic conditions in these regions - a high radiant heat load, especially - may require adjustments in physiology and behavior of the animal to enable their survival. The increased respiratory rate and rectal temperature, with seeking behavioral patterns reduced grazing time and increased idle time are recurrent in the literature as the main physiological and behavioral responses of sheep grazing in high radiant heat load environments. The presence of shadow, natural or artificial, can encourage and facilitate thermolysis physiological adjustments sheep without harm, predominantly, your metabolism. Thus, the objective of compiling information on the main patterns of behavior, as well as major physiological responses of sheep grazing in semi-arid zones.