Addressing Worker Safety in Extreme Heat

Workplace heat deaths and illnesses are rising due to intensifying heat waves driven by climate change. Heat is the number one cause of weather-related fatalities. According to the Bureau of Labor Statistics (BLS) data, 55 workers died from environmental heat exposure in 2023, up from 43 in 2022. Experts estimate the true number of deaths is likely in the thousands because symptoms can be ambiguous and companies often fail to report them.

The lack of a comprehensive federal heat standard is a key factor in rising workplace heat-related deaths. While the Occupational Safety and Health Administration (OSHA) has a general duty to protect workers, it currently lacks specific, enforceable national regulations for heat stress.

However, the agency is seeking to fill that gap. On August 30, 2024, OSHA published a Notice of Proposed Rulemaking for a federal standard on “Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings.” This proposed rule would apply to most workplaces and includes specific requirements based on heat triggers.

In addition, several states have enacted standards for heat exposure that employers in those states must follow. Employers should be building or updating their heat illness prevention plans and taking steps to provide heat protection in the workplace.

Progress in the Rulemaking Process

On January 20, 2025, President Trump issued a “Regulatory Freeze Pending Review” memorandum that applied broadly to all new and pending federal regulations. However, he did not cancel the occupational heat safety rule outright. OSHA has continued to work on it due to bureaucratic momentum and pressure from advocacy groups and career staff.

OSHA’s proposed heat standard uses a two-tier system based on the heat index (temperature plus humidity). The initial heat trigger (80°F) mandates basic safety measures, such as cool water (1 quart per hour per employee) and regular breaks as needed in the shade or air conditioning. It also requires acclimatization for new or returning workers. The high heat trigger (90°F) activates stricter, mandatory measures, such as regular paid breaks, increased monitoring (a buddy system), and regular hazard alerts.

The proposed standard would also require employers to develop a comprehensive written Heat Injury and Illness Prevention Plan (HIIPP) that identifies heat hazards and implements control measures. Documentation must include site-specific risk assessments, emergency protocols, and proof of training for both employees and supervisors.

OSHA’s Stopgap Program Has Expired

OSHA created the National Emphasis Program (NEP) on Outdoor and Indoor Heat-Related Hazards on April 8, 2022. The NEP was intended as a temporary enforcement tool while OSHA works toward a permanent standard. It was originally set to expire on April 8, 2025, but OSHA extended it through April 8, 2026.

An NEP is a temporary, high-priority enforcement strategy focusing resources on specific hazardous industries or safety issues. NEPs combine targeted, unannounced inspections with outreach to reduce injuries and fatalities, using data to identify sectors with high accident rates.

Through the NEP on heat hazards, OSHA targeted industries with high exposure to heat, particularly in construction, agriculture, and manufacturing, with the goal of reducing heat-related illnesses and fatalities. The agency conducted approximately 7,000 programmed inspections of indoor and outdoor workplaces between April 2022 and late 2024.

OSHA held informal public hearings on the proposed heat standard from June 16 through July 2, 2025. The deadline for submitting post-hearing comments was extended to October 30, 2025, but OSHA has not provided a target date for final action on the rule. OSHA allowed the NEP to expire on April 8, 2026.

Application of the General Duty Clause

Although the NEP has lapsed, OSHA continues to enforce heat safety through the General Duty Clause (Section 5(a)(1)) of the Occupational Safety and Health Act of 1970, which requires employers to provide a workplace free from recognized hazards. In other words, an employer must protect employees from known hazards even if there is no specific OSHA regulation addressing them.

Heat is a recognized hazard, and the National Institute for Occupational Safety and Health (NIOSH) has developed criteria for reducing the risk of heat stress. These criteria establish recommended exposure limits focusing on acclimatization, work/rest schedules, and physiological monitoring.

OSHA often uses the NIOSH criteria and National Weather Service data to establish that an employer knew or should have known about the danger. OSHA requires employers to implement measures such as providing water, rest breaks in shade, acclimatization plans for new workers, and emergency training.

The effectiveness of the General Duty Clause has been tested legally. In Secretary of Labor v. A.H. Sturgill Roofing, Inc. (2019), the Occupational Safety and Health Review Commission (OSHRC) vacated OSHA citations against a roofing company following a worker’s heat-related death. In a 2-1 decision, OSHRC held that “excessive heat” was too vague to define without specific OSHA standards.

The case did not render the General Duty Clause unenforceable, but it did set a much higher bar. OSHA must prove that workplace conditions posed a risk of death or serious physical harm. The agency must also show that the employer or their industry recognized that those specific conditions were hazardous and there was a practical and effective way for the employer to reduce the specific hazard.

State Standards for Occupational Heat Safety

Seven states — California, Colorado, Maryland, Minnesota, Nevada, Oregon, and Washington — have enacted specific occupational heat safety standards. Common requirements include access to cool, potable water and shaded rest areas. Employers must implement procedures for allowing new or returning workers to get used to heat. They must also train employees on heat illness signs and safety protocols and develop written procedures for handling heat-related illness.

California has comprehensive rules covering both indoor (82°F+) and outdoor (80°F+) workplaces. Mandates include shade, water, rest breaks, and acclimatization for new workers. Oregon focuses on high-heat conditions (80°F+), requiring employers to provide shade, drinking water, and emergency medical plans. Washington has strict outdoor heat exposure safety programs, with specific requirements for water, shade, and mandatory paid breaks, especially at high-heat thresholds (90°F+).

Minnesota focuses strictly on indoor, industrial, and agricultural settings, requiring ventilation and control of heat-producing equipment. Colorado focuses on agricultural workers, requiring access to shade and water as well as paid rest breaks in high-temperature conditions. Maryland and Nevada recently adopted standards protecting indoor and outdoor workers.

In 2025, 18 additional states proposed heat safety legislation. In April 2026, Virginia Governor Abigail Spanberger signed legislation directing the state’s Safety and Health Codes Board to develop and adopt heat illness regulations. New Mexico has initiated formal rulemaking to create a mandatory heat illness prevention rule. New proposals increasingly cover both hot and cold extremes, addressing broader climate change effects on safety.

Guidelines for Ensuring Occupational Heat Safety

Organizations should take steps to comply with these rules and protect their workers. A comprehensive heat safety plan should focus on adequate water, rest, and shade, and it should limit heavy work during the hottest parts of the day. New and returning workers are at higher risk and should be gradually acclimated over 7 to 14 days.

For outdoor workers, organizations can use the OSHA-NIOSH Heat Safety Tool app for real-time monitoring of local heat conditions. Indoor workplace heat can be mitigated by increasing air velocity, using reflective shields, providing air-conditioned break areas, and installing spot cooling. Workers should be encouraged to wear lightweight, breathable, and light-colored clothing (if outdoors).

Organizations should monitor workers for heat-related illness symptoms, such as dizziness, nausea, and cramps. They should train employees to recognize heat illnesses and implement a buddy system. Emergency response procedures should be developed as mandated by the OSHA General Duty Clause.

While these common-sense guidelines can help reduce the risk of heat illness, organizations should engage counsel to ensure that they are compliant with the latest regulations. As climate change continues to bring extreme temperatures, protecting workers from heat will become increasingly critical.

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