Heat Stress:Working in hot and/or humid conditions can go beyond discomfort and potentially lead to a heat-related illness, which, in severe cases, can be fatal.

This information page sheds light on the causes and origins of heat stress, various types of heat-related illnesses, and precautionary measures.

Factors contributing to heat-related illnesses include:

• Wearing extensive personal protective equipment, such as hazmat suits.
• Exposure to heat from extremely hot or molten materials, as found in places like foundries, steel mills, bakeries, smelters, glass factories, and furnaces.
• Sun exposure during outdoor work, including construction, road repair, open-pit mining, and agriculture.
• High humidity levels, common in environments like laundries, restaurant kitchens, and canneries.
• Internal body heat generated from strenuous manual labor.

Heat Regulation by the Body:The human body manages heat gain and loss through internal processes and interactions with the environment. Heat exchange occurs through:

• Radiation: Gaining heat from hot objects and losing heat to cold objects without direct contact.
• Convection: Exchanging heat with the surrounding air, gaining from hot air and losing to cold air contacting the skin.
• Evaporation of sweat: Cooling effect more pronounced in high wind speeds and low humidity. In hot and humid workplaces, sweat evaporation's cooling impact is limited, while in hot and dry environments, it depends on the body's sweat production.

Minor heat exchange methods like conduction and breathing are usually disregarded when assessing the body's heat load.

Individual Variances:People react differently to heat, influenced by factors such as:

• General health
• Body weight (being overweight or obese can hinder heat tolerance)
• Age, especially for individuals over 45
• Overall fitness level affecting susceptibility to extreme heat
• Certain prescription or illicit drug use
• Medical conditions, requiring special precautions for those with heart disease, high blood pressure, pregnancy, respiratory disease, diabetes, skin diseases, or rashes.

Additional considerations include circulatory system capacity, sweat production, and the ability to regulate electrolyte balance.