Many workers are exposed to direct solar radiation. In these conditions the workers may suffer damage to health due to an excessive increase in body temperature, or to the loss of liquids. Were carried out tests to determine if the use of screens made of various materials can reduce the physiological effects. Using the indexes WBGT and PHS were calculated the internal body temperature and the amount of fluids lost, before and after use of the screen. The best screens were those made of cardboard, newspaper paper and beach umbrellas.