What is Heat Stress?

Heat stress is a term used to describe a variety of conditions known to occur in people working or recreating in high heat. The high heat can lead eventually to overheating and potentially serious illness. In some cases, heat-related illness can lead to death. Being aware of the risks and signs of heat stress can help people avoid heat-related disorders and their associated complications.

The human body uses a number of means to regulate temperature. When someone is hot because of physical exertion or ambient heat caused by hot weather or working conditions, the body increases the flow of blood to the skin to facilitate heat loss, sweats, and changes the breathing rate. All of these steps are designed to prevent heat stress by keeping the body in a comfortable temperature range. If the conditions persist or someone is not well, however, the body will not be able to cool down quickly enough, and the patient can develop heat stress.

Mild heat stress can include things like rashes and “prickly heat,” where the skin feels prickled and irritable from heat. People can also develop muscle cramps or feel faint as a result of heat stress. More seriously, the body can start to go into shutdown as the organs are unable to cope with the high heat, and the patient experiences heat stroke. Heat stroke can be associated with symptoms like confusion, disorientation, clammy skin, difficulty breathing, fainting, bright blotches on the skin, and behavioral changes.

Preventing heat stress relies on keeping the body as cool and hydrated as possible. People working in hot conditions benefit from frequent breaks, access to water, and a resting location away from the heat. This can be something like an air conditioned breakroom or a tent, allowing workers to cool down before returning to work. People playing outdoors in high heat conditions should drink lots of water and remember to rest in the shade. Wearing protective clothing to keep the body cool can also help.

People new to hot conditions can be more at risk of heat stress because their bodies are not adapted to the heat. Travelers, people who have just relocated, and individuals starting new jobs with a hot working environment should take it slow for the first few days to give their bodies time to adjust. If they start to feel faint, dizzy, or nauseous, they should seek an area to cool down, drink some water, and rest until they feel batter. People who develop severe symptoms like an altered level of consciousness, vomiting, diarrhea, and difficulty breathing require immediate medical attention.