The proposed standard would apply to all employers conducting outdoor and indoor work in general industry, construction, maritime and agriculture sectors. Short-duration employees, emergency responders and workers at indoor sites below 80°F would be excluded. 

Rule's Requirements

Under the rule, employers would be required to develop an injury and illness prevention plan to control heat hazards in workplaces affected by excessive heat—anything above the threshold of 80°F. The plan would require employers to evaluate heat risks and, when heat increases risks to workers, implement requirements for drinking water, rest breaks and control of indoor heat. It would also require a plan to protect new or returning workers unaccustomed to working in high heat conditions.

“Workers all over the country are passing out, suffering heat stroke and dying from heat exposure from just doing their jobs, and something must be done to protect them,” said Doug Parker, assistant labor secretary for occupational safety and health. He added that the rule not only protects workers, it is “practical and workable for employers.”

Workers’ safety groups praised the rule. “We are motivated and encouraged by the latest news from OSHA, as it signifies a vital advancement in worker safety,” said Jessica Martinez, co-executive director of the National Council for Occupational Safety and Health, a coalition of worker and safety advocates. “Extreme heat poses serious risks, including heat exhaustion, heat stroke and fatalities, affecting both outdoor and indoor environments. As climate change raises global temperatures, comprehensive heat protection standards are increasingly urgent.”

Kristina Dahl, principal climate scientist for the Union of Concerned Scientists, notes that people who work outdoors have a 35% higher risk of dying from heat exposure than the general population. “The deaths of U.S. outdoor workers each year are largely preventable if employers are required to meet workers’ basic needs for water, shade and rest,” she said in a statement.

Industry groups oppose the rule, saying that it lacks flexibility that employers need. Greg Sizemore, vice president of health, safety, environment and workforce development at the Associated Builders and Contractors, said employers should be able to develop their own safety plans that are uniquely geared to specific project sites. “Our members work to ensure that jobsites are safe and implement the most appropriate practices for working in extreme heat conditions that focus on the individual worker, based on the Center for Disease Control’s recommendations,” he said in a statement.

Sizemore added that “protections must be flexible in response to the fluid nature of the construction environment, and unfortunately, some of the unworkable provisions in the proposed rule could weaken contractor efforts to prevent heat stress for workers.”

Jordan Barab, a former deputy secretary of labor at OSHA, says the ultimate fate of the heat proposal is unclear. The rule would not become final before the end of the year, and a new administration would likely nix the proposal, he says.

If the rule is finalized, it will inevitably face legal challenges, he says, adding that the proposal is the first OSHA standard to be issued in the “post-Chevron era,” referring to the Supreme Court’s June 28 Loper Bright v Raimondo decision that struck down a precedent setting 1980s ruling that authorizes federal agencies to fill gaps in laws with new regulation.

Barab says that in the absence of the deference to agency opinion that the Chevron doctrine allowed, it’s unclear what criteria judges will use to determine the legality of OSHA’s heat standard. “There’s an incredible amount of work and all kinds of science behind these issues,” he says, but, depending on which courts hear the challenges, some judges “might decide they know more about how to protect workers than the scientific experts and OSHA do.”