Heat stress is a condition that occurs when the body is unable to get rid of excess heat, causing the bodys core temperature to rise and the heart rate to increase. It can result from exposure to high air temperatures, radiant heat sources, high humidity, direct physical contact with hot objects, and strenuous physical activities. Heat stress can lead to heat-related illnesses, such as heat stroke, heat exhaustion, heat cramps, heat rashes, and chronic kidney disease. Symptoms of heat stress include loss of concentration, difficulty focusing on a task, irritability, sickness, and fainting. Heat stress can also increase the risk of injuries in workers, such as burns from accidental contact with hot surfaces or steam, and may account for an increase in workplace accidents and a decrease in worker productivity. Workers at greater risk of heat stress include those who are 65 years of age or older, are overweight, have heart disease or high blood pressure, or take medications that may be affected by extreme heat. To prevent heat stress, employers should provide training to workers so they understand what heat stress is, how it affects their health and safety, and how it can be prevented. Workers should also be aware of their risk for heat illness and should ensure they drink plenty of water and take breaks in cool places to avoid any severe impacts.