Although OSHA does not have a specific regulation covering heat stress hazards, the "General Duty Clause," in Section 5(a)(1) of the Occupational Safety and Health Act of 1970, requires each employer to furnish each employee with, "employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm." OSHA has used the General Duty Clause to cite employers that have allowed employees to be exposed to potential serious physical harm from excessively hot work environments.
Operations involving high air temperatures, radiant heat sources, high humidity, direct physical contact with hot objects, or strenuous physical activities have a high potential for inducing heat stress for employees engaged in such operations. Outdoor operations, particularly those conducted in hot weather, such as construction, refining, asbestos removal, and hazardous waste site activities are also likely to cause heat stress among exposed workers. Workers who wear semi permeable or impermeable protective clothing are particularly at risk.