When the Workplace Overheats

Occupational Heat Exposure, Regulation, and Workers' Compensation in a Warming Climate

Heat is the deadliest weather hazard American workers face, and the law is racing to catch up. Heat-related illness is the leading cause of weather-related death in the United States, and thousands of workers each year suffer heat exhaustion, heat stroke, syncope, and related conditions when they labor in hot, humid, and physically demanding environments. As average temperatures climb and a powerful new El Niño builds in the Pacific, employers, insurers, and counsel should expect the 2026 season to test both safety programs and compensation systems.

The Human and Medical Toll

Heat-related illness is a spectrum, and the most severe end of it is a medical emergency. Heat stroke occurs when the body loses its ability to regulate temperature, with the core temperature climbing toward and past 104 degrees Fahrenheit. The consequences are grave, ranging from confusion, seizures, and loss of consciousness to permanent damage to the brain, kidneys, heart, and other organs, and in many cases, death. The A.H. Sturgill Roofing matter illustrates the trajectory: a 60-year-old temporary worker on his first day collapsed on a commercial roof, was admitted with a core body temperature of 105.4 degrees, and died three weeks later of complications from heat stroke.

Less catastrophic conditions still carry real costs. Heat exhaustion causes dizziness, nausea, heavy sweating, and a weak, rapid pulse; if left untreated, it can escalate quickly. Even without illness, heat impairs concentration, slows reaction time, and increases the risk of traumatic accidents, falls, and injuries from machinery. Risk is highest in the first days of exposure, before the body acclimatizes, which is why so many fatalities strike new or returning workers.

Climate Change and a Developing El Niño

The backdrop is a warming climate in which extreme heat events are growing longer, more frequent, and more severe. Layered on top of that long-term trend is a fast-developing El Niño. On May 14, 2026, NOAA's Climate Prediction Center upgraded the official status to an El Niño Watch, placing the odds of El Niño emerging between May and July at 82 percent and rising to 96 percent for the December through February peak window.

More striking, the federal forecast now treats a strong-to-very-strong, or so-called super, El Niño as the single most likely outcome for late 2026, with sea-surface temperature anomalies of at least two degrees Celsius. The World Meteorological Organization similarly signals a near-global dominance of above-normal land-surface temperatures in the months ahead.

El Niño does not script outcomes; it shifts probabilities, but the practical message for employers is direct: 2026 is shaping up as a year of elevated heat risk, and safety programs built for an average summer may prove inadequate.

Federal Regulation: A Standard Still in Progress

There is still no finalized federal standard that specifically governs workplace heat. OSHA published its Notice of Proposed Rulemaking, titled Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings, on August 30, 2024. The comment period closed January 14, 2025, an informal public hearing ran from June 16 through July 2, 2025, and the post-hearing comment period closed October 30, 2025. If finalized, it would be the first federal labor rule to address heat directly, imposing affirmative duties to evaluate and control heat in both outdoor and indoor settings, including water, rest, shade, acclimatization, training, and a written prevention plan.

Until then, OSHA enforces through the General Duty Clause of the Occupational Safety and Health Act and its National Emphasis Program on heat hazards, which was extended through April 8, 2026. That enforcement path has limits. In A.H. Sturgill Roofing, the Occupational Safety and Health Review Commission vacated heat citations in a 2-1 decision, finding OSHA had not established a recognized hazard or a feasible means of abatement, and criticized reliance on the General Duty Clause in place of a specific standard. Even so, OSHA issued more than two million dollars in heat-related penalties in 2024, so the absence of a final rule is not an absence of exposure.

State Regulation: A Patchwork Filling the Gap

In the federal vacuum, states have moved. Three states, California, Maryland, and Oregon, have standards covering both indoor and outdoor heat; Washington covers outdoor heat; Minnesota addresses indoor heat; and Colorado regulates outdoor heat in agriculture. California's indoor heat illness regulation took effect in 2024 and applies to most workplaces where indoor temperatures reach 82 degrees Fahrenheit. Maryland's standard, effective September 30, 2024, triggers at an 80-degree heat index, and Nevada began enforcing its requirements on April 29, 2025. New Mexico has advanced a proposed heat stress rule.

Most of these rules share a common core: water, rest, shade, acclimatization, and training. For multistate employers, however, the differing trigger temperatures and documentation requirements create real compliance gaps when a program is built on general best practices rather than each state's specific terms. Once OSHA finalizes a federal rule, state-plan states must adopt standards at least as effective as the federal floor.

Where Workers' Compensation Fits the Analysis

Safety regulations and workers' compensation operate on parallel tracks. OSHA standards aim to prevent injury; workers' compensation determines who pays once a worker is hurt or killed. A heat injury is generally compensable when it arises out of and in the course of employment, and compensation is typically available without regard to employer fault. Benefits can include temporary and permanent disability, medical care, and, in fatal cases, death benefits for surviving dependents.

The recurring battlegrounds are causation and coverage. Employers and carriers often dispute whether the heat illness arose from work or from an idiosyncratic personal condition, and medical evidence frequently decides the question, as postmortem electrolyte and core-temperature findings did in the litigated heat-death cases. A second battleground is employment status and the exclusive-remedy bar. In In re Hellas Construction, a Texas appellate court addressed the death of a young construction worker who collapsed from heat stroke on a worksite in 99-degree weather; the company had disputed that he was its employee, and the court routed the threshold employment question to the Division of Workers' Compensation before the family's tort suit could proceed. The case shows how the same fatality can implicate OSHA enforcement, the workers' compensation system, and civil tort liability at once, with the employment determination controlling which door a family may use.

For practitioners, the lesson is to treat heat claims as occupational-exposure claims, document the working conditions and weather contemporaneously, secure prompt medical evaluation and records, and recognize that an employer's regulatory compliance, or its failure, can shape both the compensation claim and any parallel litigation.

Preparing for a Hotter Season

With a super El Niño the most likely scenario for late 2026, a maturing patchwork of state standards, and a federal rule that may yet be finalized, the prudent course is to prepare now. Employers should build heat programs to the strictest applicable standard, train supervisors to recognize early symptoms, and protect new and returning workers during acclimatization. Workers and their counsel should know that heat injuries are compensable occupational events and act quickly to preserve medical and environmental proof. The heat is coming. The legal infrastructure around it is still taking shape.

Sources

1. OSHA, Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings Rulemaking, osha.gov/heat-exposure/rulemaking.
2. NOAA Climate Prediction Center, ENSO Diagnostic Discussion (El Niño Watch, May 14, 2026), cpc.ncep.noaa.gov ENSO advisory.
3. World Meteorological Organization, Likelihood Increases of El Niño (Apr. 2026), wmo.int El Niño update.
4. Congressional Research Service, OSHA Regulation of Employee Exposure to Heat (state standards summary), congress.gov/crs-product/IN11701.
5. Secretary of Labor v. A.H. Sturgill Roofing, Inc., OSHRC No. 13-0224 (Feb. 28, 2019), oshrc.gov decision.
6. In re Hellas Construction, Inc., No. 03-21-00182-CV (Tex. App.—Austin July 28, 2022), Justia.
7. Federal Register, Heat Injury and Illness Prevention NPRM (Aug. 30, 2024), federalregister.gov.

About the Author

Jon L. Gelman of Wayne, NJ is the author of NJ Workers' Compensation Law (West-Thomson-Reuters) and co-author of Modern Workers' Compensation Law (West-Thomson-Reuters).

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