Concern grows in many sectors and industries about the toll that working in the heat—especially outdoors—can have on employees’ health and well-being. Unfortunately, the potential solutions are not necessarily simple or one-size-fits-all. 

“Over the past couple of decades, there has been growing concern about heat-related illnesses among electricians who work outdoors, especially utility workers,” said Eric Bauman, principal technical leader and program manager of occupational health and safety for the Electric Power Research Institute (EPRI), Palo Alto, Calif. 

EPRI-sponsored research with the University of Ottawa— which included field research with electric utility workers performing work—shows that there can be individual variability in response to heat stress. These factors include age, gender, fitness levels, hydration and more.

“We also know that measuring heart rate and heart rate variability do not necessarily correlate well to heat stress, and even measuring core temperature does not necessarily represent workers’ capacity to work,” he said. 

For example, workers can experience sustained increases in core temperatures that exceed the threshold limit values (TLVs), defined as a safe limit of 38.0°C (100.4°F) while working under work-rest allocations specified in the TLVs. 

“Using science-based worker education, policies and practices acknowledging individual variability are important in keeping workers safe and productive,” Bauman said. “As such, addressing heat stress is one of many challenges facing electric sector workers.”

Past attempts

Over the years, various organizations have attempted to provide guidance about reducing worker’s heat stress-related illnesses. One of the most consistent and active has been the National Institute for Occupational Safety and Health (NIOSH). In 2016, for example, NIOSH updated its formal “Criteria for a Recommended Standard: Occupational Exposure to Heat and Hot Environments.”

In the introduction to this document, NIOSH notes that: “Occupational exposure to heat can result in injuries, disease, reduced productivity, and death. To address this hazard, the NIOSH has evaluated the scientific data on heat stress and hot environments and has updated the ‘Criteria for a Recommended Standard: Occupational Exposures to Hot Environments.’ This document was last updated in 1986, and in recent years, including during the Deepwater Horizon oil spill response of 2010, questions were raised regarding the need for revision to reflect recent research and findings. This revision includes additional information about the physiological changes that result from heat stress; updated information from relevant studies, such as those on caffeine use; evidence to redefine heat stroke and associated symptoms; and updated information on physiological monitoring and personal protective equipment and clothing that can be used to control heat stress.”

Possible OSHA standard

While NIOSH’s standards were of a recommended nature, there has been talk recently about OSHA coming out with a heat stress standard that would be mandatory, if passed. If that does occur, it could possibly be within just a couple of years.

Wesley Wheeler, director of safety at the National Electrical Contractors Association, said: “One concern with a regulation for heat stress is a possible documentation requirement of worker acclimation to heat. With varying temperatures day to day, different humidity/heat index values and a transient workforce that moves from project to project on a daily basis, tracking workers in this process is a daunting task for all supervisors. Any regulation would have to address worker involvement and individual accountability as well.”

“Since it is not on the current regulatory agenda for OSHA, I don’t foresee a proposed rule in the near future—well into 2022,” said Mike McCullion, director of market sectors and safety for the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA), Chantilly, Va. 

Does McCullion envision a “source model” for OSHA’s potential foray into this initiative? 

“I believe they will look at the current state of California rule as an example of a rule that provides good guidance without being too prescriptive,” he said.

Pete Chaney, director of safety and health for the Mechanical Contractors Association of America (MCAA), Rockville, Md., also believes that, at some point in the future, an OSHA standard covering work in hot environments is likely. However, he doesn’t see it as an agency priority.

If the current administration gets a second term, he believes that we’ll see a proposed rule sometime between 2023 and 2026.

The likely incoming assistant secretary of labor for OSHA will be Douglas Parker, who currently heads Cal/OSHA and was nominated for the federal position in April. 

“As a result, I believe the standard would be based largely on the Cal/OSHA heat stress standard,” Chaney said. “Also, OSHA already provides guidance in ‘Keeping Workers Safe in the Heat,’ so a federal standard would likely include that guidance as well.” 

The Cal/OSHA standard, implemented in the mid-2000s, was spurred by a spike in the number of heat-related work incidents reported to Cal/OSHA.

The resulting permanent heat illness prevention standard was, according to Len Welsh, then Cal/OSHA acting chief, the first in the country that was designed to apply to all outdoor places of employment and those working outdoors, including construction, agricultural and landscaping workers.

Specifically, the standard focuses on six measures: provision of water, access to shade, high-heat procedures, emergency response procedures, acclimatization and training.

Implications for workers

If a national OSHA heat stress standard does come into existence, what would some of the implications be for employers who have employees working outdoors?

“Electrical contractors would have to ensure proper shade is provided to protect workers from direct sunlight, which might be challenging in some locations,” Wheeler said. “In addition, employers could be required to monitor employee temperature during heat events. Utility workers, who are required to wear FR clothing and additional PPE, could be more susceptible to heat-related issues during summer and days with a high heat index value.”

Dave Warnock, safety supervisor for Mojave Electric, Las Vegas, expressed concern over a potential “one-size-fits-all” OSHA standard on heat stress. 

“I believe there will be a very good chance that OSHA will come up with some type of proposed standard, especially due to the fact that they aren’t able to cite the General Duty Clause as they were in the past,” he said.

If and when such a standard comes up, Warnock believes it will be more specific than it was in the past, when guidance seemed to be rather vague. 

“These would include such things as personal risk factors, types of training and who gets what type of training, duties of an employer, duties of an employee, and threshold limits of heat stress values taken from American Conference of Governmental Industrial Hygienists,” he said.

Warnock also foresees a requirement for more documentation and training.

“It would likely be necessary to train the foremen to understand each employee’s health to possibly predict heat illness, possibly adding to time required in scheduling,” he said. “As a whole, it would be challenging for all construction trades that are in a hot region like this, and the possible implications would be significant.”

While Warnock is looking down the road at a possible national standard, his more pressing concern is the possibility of a new state standard on heat stress. In January 2021, Nevada’s Department of Business and Industry, Division of Industrial Relations, proposed “a regulation relating to occupational safety and health; adopting by reference certain standards relating to heat stress and strain; imposing certain duties on employers of employees who are exposed to certain high temperatures; requiring employers to provide employees with access to shade under certain circumstances; requiring an employer to provide employees with training related to heat illness; imposing certain duties on an employer of an employee who shows signs or symptoms of heat illness; providing that an employee is responsible for monitoring his or her own personal risk factors for heat illness; and providing other matters properly relating thereto.”

“SMACNA has promoted a proactive approach to preventing heat stress, including developing heat stress awareness tip cards focusing on prevention, awareness and treatment that have been popular in recent years,” McCullion said. 

“However, the difficulty for contractors in applying a heat stress illness standard is that weather varies throughout the country, and individual workers reactions to heat stress are difficult to predict and manage,” he said. “In addition, indoor and outdoor heat stressors vary, but may need to be addressed under the same standard.”

As with most health-related standards, McCullion believes it is difficult to apply one set of preventive measures since each worker is affected differently.

“Industrial hygiene concepts can be difficult for small employers that may lack personnel and resources to understand and apply the related standard requirements,” he said.

And, according to Chaney, MCAA members are already “dialed in” to protecting their workers from heat stroke, heat exhaustion, heat syncope and heat cramps. 

“They’re already providing and performing most of what the standard would require,” he said. 

As a result, MCAA does have concerns about the potential for unnecessarily challenging provisions in an OSHA standard. 

“For example, a provision such as Cal/OSHA’s requiring a full quart of filtered water per worker per hour for each entire shift could be extremely challenging on many job sites in the United States,” Chaney said. “Another example would be stipulating a single air temperature that would trigger the standard’s worker protection provisions, without consideration of humidity, working conditions such as shade or no shade, indoor versus outdoor work, etc.”

A10 Committee

In the meantime, there is other action being taken in the private sector to provide some guidance to employers related to employees who might be exposed to heat stress when working outdoors.

McCullion, for example, is a member of the subgroup focused on developing an ANSI/ASSP A10 Voluntary Consensus Standard for Heat Stress, and, he admits, finding language to address all scenarios and adequate preventive measures for heat stress is not easy.

“The challenges we are focusing on are related to how to monitor and predict the weather and each individual worker’s potential for heat stress on every work site,” he said.

Whether a national OSHA heat stress standard comes into existence or not, whether more individual states contemplate their own heat stress standards or whether other industry groups offer guidance on how employers should protect employees, EPRI’s Bauman offers some recommendations that make sense for all employers in these circumstances to implement now. 

“Based on research of electric utility workers and others, the following science-based practices have been suggested,” he said.

• Plan ahead and monitor the weather so you can adjust exposure times, such as by providing extra breaks.
• Implement progressive climate acclimation to improve heat tolerance.
• Achieve and maintain appropriate hydration levels.
• Rest in a well-ventilated, shaded area and remove outer layers of clothing, for example by establishing and using cooling oases with shade and ventilation.
• If a worker feels sick, they should lie down and apply cool, wet towels around the neck and limbs and seek immediate medical attention.
• Moderate work effort and intersperse longer rest periods with recovery or cooling strategies.
• Employ heat-strain monitors or sensors, but be aware that individuals respond differently to heat.
• Implement a peer-checking system.

For more details on the problems associated with heat stress and strategies for addressing it, see “Staying Cool” in the May 2019 issue of ELECTRICAL CONTRACTOR.