Turning Up the Heat

OSHA is looking into hot conditions for workers outdoors as well as those inside.

By Alexandra Walsh

Millions of U.S. workers are exposed to heat in their workplaces. Even though illness from exposure to heat is preventable, thousands become sick from occupational heat exposure every year, and some cases are fatal.

Heat stress killed 815 U.S. workers and seriously injured more than 70,000 workers from 1992 through 2017, according to the U.S. Department of Labor’s Bureau of Labor Statistics. However, this is likely a vast underestimate, given that injuries and illnesses are annually underreported in the United States.

Furthermore, heat is not always recognized as a cause of heat-induced injuries or deaths and can easily be misclassified because many of the symptoms overlap with other more common diagnoses. The Bureau of Labor Statistics reports that from 2011 to 2019, environmental heat cases resulted in an average of 2700 cases with days away from work.

Not only is heat the leading cause of death among all weather-related phenomena, but it is also becoming more dangerous. Case in point, 18 of the last 19 years were the hottest on record. In addition, climate change is increasing the frequency and intensity of extreme heat events, as well as increasing daily average daytime and nighttime temperatures.

Path to a Federal Heat Standard

Record-breaking heat in the United States in 2021 endangered millions of workers exposed to heat illness and injury in both indoor and outdoor work environments. However, only California, Minnesota, Washington, and the U.S. military have issued heat protections.

The Occupational Safety and Health Administration does not currently have a specific standard for hazardous heat conditions and relies on the general duty clause [OSH Act Section 5(a)(1)] to protect workers from this hazard. Notably, from 2013 through 2017, California used its heat standard to conduct 50 times more inspections resulting in a heat-related violation than OSHA did nationwide under its general duty clause.

Democratic members of the U.S. Senate urged OSHA in 2019 to initiate rulemaking to address heat stress. OSHA responded by publishing in October 2021 an “Advance Notice of Proposed Rulemaking for Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings” in the Federal Register. With this publication, OSHA is beginning the rulemaking process to consider a heat-specific workplace

A standard specific to heat-related injury and illness prevention would more clearly set forth employers’ obligations and the measures necessary to protect employees more effectively from hazardous heat. According to OSHA, the ultimate goal is to prevent and reduce the number of occupational injuries, illnesses, and fatalities that are caused by exposure to hazardous heat.

Publication of the Advance Notice of Proposed Rulemaking initiated a public comment period allowing OSHA to gather information, diverse perspectives, and technical expertise on issues that might be considered in developing a heat standard.

These issues include the scope of a standard, heat stress thresholds for workers across various industries, heat acclimatization planning, and heat exposure monitoring as well as the nature, types, and effectiveness of controls that may be required as part of a standard.

Publishing the Advance Notice is one of a series of OSHA efforts to address heat hazards in the workplace. OSHA also announced last fall a National Enforcement Initiative and a National Emphasis Program in April of this year focused on heat hazards.

National Enforcement Initiative

The enforcement initiative OSHA announced last fall is one with a goal to prevent and protect employees from serious heat-related illnesses and deaths while working in hazardous hot indoor or outdoor environments. It expands on the agency’s ongoing heat-related illness prevention campaign by setting forth the enforcement component and reiterating its compliance assistance and outreach efforts.

The initiative prioritizes heat-related interventions and inspections of work activities on days when the heat index exceeds 80℉. OSHA notes a heat index at this level indicates a need to increase enforcement efforts to identify potential heat-related hazards present in working conditions, before the occurrence of an illness or death.

Employers are encouraged to activate proactive interventions such as providing water, rest, and shade, and other important prevention measures such as acclimating new or returning workers to conditions in the job setting.

The enforcement initiatives place special emphasis on adapting to changes in the work environment. Record hot temperatures create excessive heat working conditions that are especially dangerous to workers who have not been acclimated.

Acclimatization is a process by which a person gradually increases their exposure time in hot environmental conditions, thus causing beneficial physiological changes to prevent heat-related illnesses by properly regulating a person’s body temperature. It is essential for employers of new or returning workers to increase their workloads gradually and be sure to provide more frequent breaks as workers adjust themselves to ambient conditions.

However, the most successful efforts to prevent heat-related illnesses and deaths include more than just programs where workers become acclimated.

OSHA takes note that employers should use a combination of improvement methods—encouraging or mandating that employees regularly take rest breaks, provide shaded areas to workers, and supplying everyone with water.

Employers should train employees about heat-related illnesses, how to spot their common symptoms, and what to do when a worker suspects a heat-related illness is occurring with a colleague. Employers should also take periodic measurements to determine employees’ heat exposure and provide follow-up protection to employees from heat as needed.

National Emphasis Program

OSHA’s most recent actions on preventing heat illness in workers, that became effective this April, is a National Emphasis Program (NEP) focused on heat hazards.

Under this program, OSHA will be conducting proactive inspections for heat-related hazards—in both outdoor and indoor work environments. It is necessary for employers to have appropriate safety measures already in place to protect employees from such hazards before potentially coming under OSHA’s spotlight.

Namely, NEP outlines certain triggers for heat-related inspections:

  • When conducting other non-heat-related investigations, OSHA will open a heat-related inspection into any hazardous heat conditions observed or reported.
  • When the heat index is expected to be 80℉ or more, OSHA will inquire about heat-related hazard prevention programs during inspections.
  • When the National Weather Service has announced a heat warning or advisory for a local area, OSHA will use neutral, objective criteria to select employers for preplanned inspections in high-risk industries in that area.
  • When the Wage and Hour Division of the Department of Labor is investigating reported inadequate working or living conditions, it is encouraged to refer information about potential heat-related hazards to OSHA.

The bottom line is employers should be aware, particularly on hot days, that OSHA may come to inspect. If that happens, NEP mandates several steps OSHA must take in inspecting heat-related hazards:

  • Review injury and illness logs and incident reports for entries indicating heat-related illness.
  • Review records of heat-related emergency room visits or ambulance transport, even if hospitalization did not occur.
  • Interview workers for heat illness symptoms like headache, dizziness, fainting, dehydration.
  • Determine if the employer maintains a heat illness and injury prevention program, and whether the program addresses hydration, breaks, shade, acclimatization, and training.
  • Document relevant conditions such as the heat index, any National Weather Service heat alerts, type of heat source (direct sunlight, equipment, proximity to heat source), any injured employee’s exertion level, and duration of exposure to heat and the like.


Given OSHA’s keen focus on heat hazards, employers—especially those in targeted industries including water well operations—should be considering several steps ahead of time to best protect themselves and their employees.

For example, employers should make sure their safety policies directly address heat-related hazards, provide adjustment periods for new employees who are not yet adapted to working full days in high heat, develop a means to monitor the heat index and employees’ exposure to heat, and train employees on how to respond to heat-related illness and emergencies.

It may not only save you OSHA headaches, but it will be good for the health and safety of all employees.

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Alexandra Walsh is the vice president of Association Vision, a Washington, D.C.–area communications company. She has extensive experience in management positions with a range of organizations.