The Occupational Safety and Health Administration plans to propose a new rule requiring employers to protect employees exposed to high temperatures at work. This federal government regulation is the first of its kind to provide protection from heat on the job. As the summer months arrive and heat records rise, employers would do well to examine OSHA’s proposal, and to understand the legal pitfalls facing employers under the National Labor Relations Act (NLRA) and the Labor Management Relations Act (LMRA), should employees complain about or walk off the job due to excessive heat in the workplace.

The Growing Concern and Focus on Heat Stress

According to the Bureau of Labor Statistics (BLS) Census of Fatal Occupational Injuries, heat exposure killed 907 workers in the US from 1992-2019, with an average of 32 fatalities per year. The three-year annual average has doubled since the early 1990’s. According to the National Weather Service, heat remains the leading cause of death among all weather-related phenomena combined, and the Federal Health and Human Services Department cites deaths from heat as the greatest threat to human health posed by climate change. James Frederick, OSHA’s acting director, has said heat safety is a “priority” for the Biden administration. Accordingly, the issue of heat stress in the workplace is a critical issue facing employers.

OSHA’s Proposed Rule

The rule as described so far in OSHA’s notice of proposed rulemaking, “Heat Illness Prevention in Outdoor and Indoor Work Settings,” aims to set clearer standards for work breaks, hydration, air conditioning/shade, and medical monitoring to employees. It would likely include two heat index thresholds, one at 80°F and the other at 90°F. The standards would account for work performed outdoors or indoors as well as light duty versus heavy work. The agency described similar thresholds used in states like California and Oregon, as well as the U.S. military. OSHA also published a regulatory framework to outline potential options for the various elements of the proposed rule. The public is invited to submit feedback for regulators as they promulgate rules in this area to

Current OSHA Requirements

Although OSHA does not have a specific standard governing hazardous heat conditions at workplaces, the agency currently enforces the “General Duty Clause,” which protects employees from recognized hazards that cause or are likely to cause death or serious physical harm. OSHA has historically relied on the General Duty Clause to cite employers for heat-related hazards. However, OSHA says the General Duty Clause is insufficient without express hazardous heat exposure thresholds or specifics on how employers must eliminate or reduce employees’ such exposure. The agency says it needs a standard specific to heat-related injury and illness prevention to clearly set forth employer obligations and to help employers identify the measures necessary to protect employees from hazardous heat.

Additional Federal Laws That May Protect Employees Who Stop Work in Protest of Heat Conditions

In addition to OSHA’s authority to cite employers for hazardous heat conditions and OSHA’s protections against retaliation for employees who complain about work-related hazards, employees may have the right to engage in self-help under the NLRA and LMRA when they feel temperatures are too high to safely work. Reports of workers walking off the job due to high temperatures tend to increase this time of year.


Section 7 of the NLRA guarantees non-supervisory employees the right to engage in protected concerted activity—banding together with co-workers to improve working conditions, with or without a union. The NLRB interprets Section 7 to specifically protect the rights of employees to strike over what they honestly believe to be unsafe and unhealthy working conditions. Examples of Section 7 activity regarding high heat conditions in the workplace may take the form of employees posting complaints on social media about a broken air conditioner, or employees working outdoors engaging in a strike over a lack of hydration or rest breaks. It is important to note Section 7 may also protect sympathy strikes—a work stoppage in sympathy for co-workers striking over hot working conditions.


Section 502 of the LMRA also protects employees (both union and non-union) who, in good faith, stop work, “because of abnormally dangerous conditions for work at the place of employment[.]” Significantly, unlike Section 7 of the NLRA that protects only “concerted” activity, Section 502 protects the conduct of individuals. However, the burden falls on employees to establish the “abnormally dangerous conditions.” In unionized workplaces, Section 502 provides a limited exception to any express or implied no-strike obligation, meaning that participants in such work stoppage would be protected from termination, injunctions, etc., when they believe, in good faith, that cessation of work is necessary to protect them from immediate harm.


With summer upon us and 2024 already setting record high temperatures following the El Niño event at the start of this year, Employers should stay abreast of OSHA’s rulemaking related to high heat exposure. Employers must also bear in mind the NLRA and LMRA protections for workers who may engage in self-help, including walk outs, if they feel workplace heat creates a dangerous environment. In addition, state and local laws may also afford employees protection. Employers should always consult legal counsel for specific guidance on how to respond to work stoppages or other interferences with operations. Husch Blackwell’s experienced traditional labor attorneys stand ready to help.