The arrival of the hot summer season brings the risks and dangers of heat exposure for many employees throughout the United States. The Occupational Safety and Health Administration (OSHA) has issued a reminder to employers of their duty to protect employees, along with some guidance on ways to recognize and mitigate the risks of heat exposure.

How Hot Does it Need to Be?

Serious heat-related illnesses can occur on normal summer days, when temperatures are not extreme. A good rule of thumb is that workers need additional protective measures whenever the Heat Index is 80 degrees Fahrenheit or above. However, sports physiologists have found that even as low as 65 degrees Fahrenheit may pose a risk of heat-related illnesses when workload is very heavy or strenuous.

CA Note: For California employers, Cal/OSHA Heat Illness Prevention Standard §3395 additionally requires that employers implement additional high heat procedures when the temperature equals or exceeds 95 degrees Fahrenheit.

Does It Matter Whether Workers are Indoors or Outdoors?

No. OSHA’s guidance extends to any work environment that presents occupational risk factors, including heavy physical activity, warm or hot environmental conditions, lack of acclimatization, and wearing clothing that holds in body heat. OSHA also identifies a non-exclusive list of industries at risk:

OSHA recommends that employers utilize its assessment tools, which are based on levels of physical activity and wet bulb globe temperature readings, to evaluate the combination of body heat and environmental heat to identify what risks their workers face for heat stress.

CA Note: For California employers, Cal/OSHA Heat Illness Prevention Standard §3395 applies to outdoor place of employment.

What Steps to Prevent Heat Exposure?

• Offer water, rest, shade, and ventilation. Employers should encourage workers to drink water every 15 minutes, and take frequent rest breaks in shaded or air conditioned areas. Employers also should use cooling fans and, whenever possible, schedule work at a cooler time of the day. OSHA has published a comprehensive list of best practices in considering what engineering controls, work practices, and personal protective equipment should be in place.

  • CA Note: For California employers, Cal/OSHA Heat Illness Prevention Standard §3395 mandates that employers provide cool drinking water free of charge, shade for employees when the outdoor temperature exceeds 80 degrees, and preventive cool-down rests that are monitored by another employee.

• Create a Plan. OSHA recommends that employers create a heat illness prevention plan, with elements addressing: how workers will gradually develop heat tolerance, supervision of workers, a protocol for summoning medical assistance, what engineer controls and work practices will be used to reduce heat stress, measurement of heat stress, a response when the National Weather Service issues a heat advisory, how to identify heat hazards, and what training will be provided to workers and supervisors.

• Require Training. Employers should provide training to workers on the hazards of heat exposure and how to prevent illness. New and temporary workers are most at risk to the hazards of excessive heat. OSHA’s website offers additional guidance on building heat tolerance in its recommendations for establishing a plan to protect new workers from heat illness.

• Implement Supervision. As heat conditions can change rapidly, OSHA recommends that, if feasible, at least one individual at a worksite should monitor conditions and implement the employer’s heat plan throughout the workday. This individual should undergo training, be on-site with workers, and have the capacity to report to the employer any adverse heat-related conditions or signs and symptoms of heat related illness experienced by any of the workers.