The aim of the study was to observe the physiological responses of non-acclimatized native sheep subjected to different environmental conditions in a climatic chamber. Eighteen male sheep, six of each breed, were distributed in an entirely randomized design and submitted to eight treatments (four air temperatures -T20, T25, T30 and T35ºC; and four air temperatures + environmental modification -T20+WA, T25+HF, T30+HF and T35+HF ºC), and 60 to 80% relative humidity. The physiological variables heart rate (HR) and respiratory rate (RR), and rectal temperature (RT), skin temperature (ST) and coat surface temperature (CT) were collected. In general, the physiological responses of the animals showed an interaction between them, where each one of these responses is dependent on each other, and there is susceptibility of these physiological responses to climate change. Understanding the functioning of the physiological mechanisms for heat dissipation, it is possible to adapt the animal management in order to increase production without increasing heat, which may cause stress to the animal.