Employers under the law, and specifically the General Duty Clause, are required to provide employees with workplaces free of recognized safety hazards. This includes protecting workers from situations involving extreme heat. Employers therefore should establish a heat illness prevention program. Operations involving high air temperatures, radiant heat sources, high humidity, and strenuous physical activities in high heat situations have a high potential for causing heat-related illness. Industries including foundries, brick-firing and ceramic plants, glass product facilities, boiler operations, bakeries, laundries, mining sites, and other similar workplaces expose employees to heat hazards. Outdoor operations and work conducted in hot weather and direct sun, such as lawn mowing operations, landscaping, farm work, constructions, emergency response operations, and hazardous waste site jobs, also exposure employees to heat hazards.
Why is heat such a hazard to workers? When the air temperature is warmer than the normal body temperature, cooling of the body through sweating becomes more difficult. Sweating is effective only if the humidity level is low enough to allow evaporation, and if the fluids and salts that are lost in the sweat are adequately replaced. Thus, excessive heat exposure can cause a range of heat-related illnesses, from heat rash to heat stroke. Heat rash is skin irritation caused by sweat that does not evaporate. Heat cramps are caused by the loss of body salts and fluid during sweating. Low salt levels in muscles cause painful cramps. Heat exhaustion is the body’s response to loss of water and salt from heavy sweating. Signs include headache, nausea, dizziness, weakness, irritability, thirst, and very heavy sweating. Immediate attention should be directed to a worker suffering heat exhaustion including rest in a cool, shady area with plenty of water and cool liquids to drink. Heat stroke is the most serious form of heat-related illness. This occurs when the body is unable to regulate its core temperature. Sweating stops, the skin becomes dry, the individual may faint or become confused, or ultimately may suffer seizures. Immediate first-aid measure by medical professionals are necessary to treat heat stroke.
How can employers minimize and prevent the hazard of heat-related illnesses? First, employers should conduct a hazard assessment of the workplace. This is required not only under the General Duty Clause in Section 5(a)(1), but also in the Personal Protective Equipment standard at 29 CFR 1910.132. As always, after the hazard assessment is performed, engineering controls should be considered to make the work environment cooler and reduce the exposure to heat. For example, air conditioning, increased ventilation, cooling fans, reflective shields to redirect radiant heat, insulation of hot surfaces, and local exhaust ventilation at points of high heat production, are engineering controls used to reduce exposure to heat. Employers should also be aware that Sanitation standards found in multiple regulations in the Occupational Safety and Health Act require employers to provide potable drinking water that is readily accessible for employees. Beyond engineering controls, employers should develop a written heat exposure plan that includes, for example, directions specifying what to do if an employee shows signs of heat-related illness, adequate drinking water close to the work area, rotating job functions among employees to minimize overexertion and heat exposure, and procedures to assist employees with gradual exposure to heat which may include more frequent breaks during the initial period of employment. Further recommendations can be found at the OSHA website. Finally, employees should be trained regularly on the employer’s heat exposure plan.