Heat, Labor, and a Half-Century of Regulatory Inertia: Reforming US Worker Protections in a Warming Climate

In the summer of 2021, a heat dome settled over the Pacific Northwest with consequences that briefly forced the nation's attention onto a problem that labor researchers had been documenting for years. Farmworkers in Oregon collapsed in fields where temperatures exceeded 115°F. A roofing crew in Phoenix reported to a worksite where surface temperatures rendered standard equipment too hot to handle without burns. Warehouse employees in fulfillment centers across the Sun Belt described working conditions in which internal temperatures climbed well above what occupational health guidelines consider safe, with no enforceable federal standard requiring their employers to do anything about it.

These are not anomalies. They are, increasingly, the operational baseline for a substantial portion of the American workforce—and the regulatory architecture meant to protect those workers has not meaningfully evolved since the early years of the Occupational Safety and Health Administration.

The Epidemiological Record: A Burden That Is Growing

Heat-related illness is among the most preventable categories of occupational injury, and among the most systematically undercounted. The Bureau of Labor Statistics records approximately 35 to 40 heat-related worker fatalities annually, a figure that occupational epidemiologists regard as a substantial undercount due to attribution practices that classify heat as a contributing rather than primary cause of death in many cases. Research published in Environmental Health Perspectives and the American Journal of Industrial Medicine suggests the true annual toll may exceed 600 deaths, with non-fatal heat illness affecting hundreds of thousands more.

The burden is not distributed evenly. Agricultural workers—a population that is disproportionately Latino, often undocumented, and concentrated in states with the highest ambient heat exposure—face fatality rates from heat illness that are more than 20 times the national civilian average. Construction workers, outdoor utility crews, and employees in non-climate-controlled manufacturing and logistics facilities represent additional high-exposure populations. Crucially, the epidemiological literature consistently demonstrates that heat stress does not merely cause acute illness; it compounds cardiovascular strain, impairs cognitive function and motor coordination, and increases the risk of workplace accidents with causes that may appear unrelated to temperature.

What makes this burden particularly difficult to defend from a policy standpoint is its trajectory. Climate modeling published in Nature Climate Change and reviewed by the National Oceanic and Atmospheric Administration projects substantial increases in the frequency, intensity, and geographic extent of extreme heat events across the continental United States through mid-century. The workers most exposed today will face materially worse conditions within the career spans of people currently entering the labor force.

OSHA's Structural Limitations in the Current Regulatory Framework

The Occupational Safety and Health Administration was established by the OSH Act of 1970, and while the agency has issued guidance documents and hazard alerts on heat stress over the intervening decades, it has never promulgated a binding heat illness prevention standard. In the absence of such a standard, OSHA has relied on the General Duty Clause—a provision requiring employers to maintain workplaces free from recognized serious hazards—to pursue enforcement actions in egregious cases. This approach is legally defensible but operationally inadequate: it is reactive rather than preventive, applies only after harm has occurred or been imminent, and provides employers no clear compliance benchmark.

The Biden administration initiated a rulemaking process for a federal heat standard in 2021, and a proposed rule was published in 2024 that would establish requirements for water access, rest breaks, shade or cooling areas, and acclimatization protocols. That rulemaking, however, remains incomplete and faces the institutional uncertainties characteristic of regulatory processes that span presidential administrations. The structural lesson is clear: voluntary guidance and intermittent enforcement are insufficient instruments for addressing a hazard that is both foreseeable and growing.

State-level action has partially filled the federal void. California, Washington, Oregon, Colorado, and Minnesota have enacted heat illness prevention regulations of varying comprehensiveness. California's standard—among the most developed in the country—mandates shade access, potable water, rest periods, and emergency response protocols for outdoor workers. The epidemiological evidence from California suggests these requirements reduce heat illness incidence, though rigorous comparative studies controlling for climate variation and workforce composition remain limited. The state patchwork, while valuable, creates inequitable geographic disparities in worker protection that only federal action can resolve.

Lessons from Scandinavian Occupational Health Policy

The Nordic countries offer a useful, if climatically distinct, reference point for what institutionally robust occupational heat protection can look like. Sweden, Norway, and Finland have developed occupational health frameworks that treat thermal environment as a core ergonomic parameter, subject to the same systematic risk assessment and employer obligation as noise, chemical exposure, or musculoskeletal load. The Swedish Work Environment Authority, for instance, requires employers to conduct formal thermal comfort assessments, implement engineering controls as the primary intervention, and document heat-related risk management as part of standard workplace safety planning.

Critically, the Scandinavian model embeds occupational health expertise within a broader social partnership structure in which trade unions hold formal consultative and enforcement roles. This institutional design accelerates the translation of emerging health evidence into updated workplace standards in ways that the adversarial US regulatory model—where rulemaking is frequently litigated and delayed—does not naturally support. The Nordic systems are not directly exportable to the American administrative context, but several of their operational features are instructive: mandatory employer risk assessment, explicit temperature thresholds triggering specific protective obligations, and acclimatization requirements for workers new to heat-intensive tasks.

These are not exotic policy innovations. They are evidence-based engineering and administrative controls that occupational health science has validated across multiple industrial settings. Their absence from binding US federal standards reflects regulatory inertia, not scientific uncertainty.

A Framework for Evidence-Based OSHA Reform

This analysis identifies three priority areas for reform that are both scientifically grounded and administratively achievable within existing OSHA statutory authority.

Finalize and strengthen the proposed federal heat standard. The rulemaking process begun in 2021 should be completed and should incorporate the strongest evidence-supported provisions: mandatory acclimatization schedules, engineering control requirements where feasible, heat index-triggered protective protocols, and anti-retaliation protections for workers who report unsafe conditions. Delay carries quantifiable human cost.

Integrate climate projection data into standard-setting. Current occupational health thresholds are calibrated to historical climate baselines. OSHA's standard-setting process should formally incorporate NOAA and EPA climate projection data so that protective thresholds reflect not only current conditions but anticipated exposure trajectories over the regulatory horizon.

Expand epidemiological surveillance infrastructure. The persistent undercounting of heat-related occupational illness reflects inadequate surveillance, not low incidence. The National Institute for Occupational Safety and Health should develop standardized attribution protocols for heat-related deaths and establish sentinel surveillance systems in high-exposure industries. Accurate data is the foundation of credible regulatory justification and enforcement.

Conclusion

The relationship between climate change and occupational health is not a future problem. It is a present one, measurable in hospital admissions, workers' compensation claims, and death certificates filed each summer across the United States. The science documenting this relationship is neither new nor contested. What is contested—and what this journal argues must be resolved in favor of protective action—is whether the regulatory institutions created to protect American workers will update their standards to reflect the world those workers actually inhabit. The answer, thus far, has been inadequate. The scientific and policy case for change has never been stronger.