When outside temperatures soar past 90 degrees, agricultural workers and anyone who works long hours in the sun can easily fall victim to heat stress. Labor supervisors should pay close attention to their workers for signs of heat exhaustion, cautions William Steinke, a Cooperative Extension farm safety specialist at UC Davis. Symptoms of heat stress include extremely rapid pulse, dizziness, disorientation, behavior change, loss of skin tone and profuse sweating, says Steinke. When these appear, the worker should be placed in the shade and allowed to rest. Water or a sports drink should be given to help the body rehydrate itself. Alcohol-based beverages should be avoided because they interfere with the body's heat regulating process. If the person fails to respond, emergency medical help should be sought. Steinke advises that frequent breaks, consumption of lots of fluids and use of wide-brimmed hats during hot weather are the best and simplest measures for preventing heat stress among farm workers.