Heat regulation accelerates at state level, federal rulemaking remains uncertain

Heat-related workplace safety has become one of the most active areas of occupational safety regulation in the United States. While the Occupational Safety and Health Administration (OSHA) continues to work toward a federal heat illness standard, states and local governments are increasingly moving ahead with their own requirements, creating a growing patchwork of obligations for employers operating across multiple jurisdictions.

In 2024, OSHA proposed its Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings, which would establish:

An initial heat trigger at 80 degrees Fahrenheit, requiring measures such as drinking water, shade, and acclimatization procedures.

A high-heat trigger at 90 degrees Fahrenheit that would require additional protections, including paid rest breaks and employee monitoring.

Midway through 2026, the rule remains under development, with the agency targeting December 2026 for a supplemental proposal before a final standard can be considered. In the absence of that finalized federal standard, OSHA continues to enforce heat-related hazards through its National Emphasis Program — most recently updated regarding heat illness in April — and the General Duty Clause of the Occupational Safety and Health Act of 1970. OSHA inspectors can cite employers for failing to protect workers from recognized heat risks.

States, meanwhile, continue to enact new heat regulations:

In 2024

Maryland’s Heat Stress Standard went into effect, covering both indoor and outdoor work and requiring employers to activate heat-mitigation plans at 80 degrees Fahrenheit and establish mandatory rest periods when temperatures exceed specified thresholds.

In 2025

Nevada OSHA began enforcement of its heat illness regulation, which requires employers with more than 10 employees to assess heat-related hazards and implement prevention measures where risks exist. Requirements may include potable water, cooling measures, employee training, monitoring of heat conditions, and emergency response procedures. Unlike many other state proposals, Nevada's rule uses a risk-based hazard assessment rather than fixed temperature thresholds. Updated guidance issued in May 2026 aligned enforcement with OSHA's revised National Emphasis Program.

In APRIL 2026

Virginia Governor Abigail Spanberger signed SB 288, which directs state regulators to develop mandatory indoor and outdoor heat standards by May 2028. The anticipated rules are expected to require worker training, access to drinking water, shaded or climate-controlled recovery areas, and procedures for periods of extreme heat exposure.

California, which last updated its heat illness prevention requirements in 2024, remains the national benchmark. California requires employers to protect workers from heat-related illnesses by providing free, cool drinking water; accessible rest areas; and mandatory five-minute preventive cooldown breaks. Outdoor requirements include shade structures at 80 degrees Fahrenheit and extra high-heat protocols at 95 degrees Fahrenheit; the indoor standard is triggered at 82 degrees Fahrenheit and requires structural engineering controls at 87 degrees Fahrenheit. Across both indoor and outdoor settings, businesses must maintain written compliance plans and deliver mandatory safety training to all employees.

Oregon and Washington also maintain comprehensive standards that require shaded rest areas, cooldown breaks, and additional protection as temperatures rise. Minnesota continues to maintain industry-specific indoor heat stress protections tied to worker exertion levels.

New Mexico has proposed mandating that employers implement written plans when heat indices reach 80 degrees Fahrenheit. The rule would also require that workers be given access to water and cooling areas and be gradually acclimated to heat exposures. Employers would also have to report all heat illnesses within 24 hours. The rulemaking process for the proposed protections has been delayed until early 2027.

Meanwhile, in June, New York City Mayor Zohran Mamdani issued an executive order directing city agencies to strengthen protections for workers exposed to extreme heat. The order gives particular attention to outdoor and gig-economy workers.

Other jurisdictions considering new requirements include:

ARIZONA

Arizona lawmakers have proposed legislation that would require employers to establish written heat mitigation programs for employees exposed to temperatures above 80 degrees Fahrenheit.

COLORADO

Colorado is considering the Extreme Temperatures Worker Protections Act, which would create a framework for collecting heat-exposure data and potentially developing future statewide standards.

GEORGIA

Georgia’s general assembly is considering proposed legislation requiring employers to provide water, shaded rest, and paid breaks when temperatures exceed 80 degrees Fahrenheit. The legislation emphasizes high-risk industries such as agriculture, construction, manufacturing, and transportation.

NEW HAMPSHIRE

New Hampshire lawmakers have introduced legislation aimed at addressing both extreme heat and extreme cold through mandatory planning and training requirements.

The momentum behind these initiatives reflects growing concern among regulators and worker advocates about the effects of rising temperatures on occupational safety. State standards generally focus on similar themes:

Ensuring access to water.

Providing rest breaks.

Supplying shaded or cooled recovery areas.

Training employees and supervisors to recognize heat illness symptoms.

Implementing acclimatization procedures for new or returning workers.

Although specific requirements vary, the overall trend is toward more prescriptive employer obligations rather than reliance on general workplace safety principles.

Business groups, however, have raised significant concerns about several of the proposed federal and state measures. Critics argue that a one-size-fits-all federal standard does not adequately account for differences among industries, work environments, geographic regions, and employee job functions.

Businesses have argued that the proposed OSHA rule would impose substantial compliance costs on employers while creating operational challenges, such as managing work schedules, staffing levels, and productivity during periods of elevated temperatures. They contend that existing state programs, industry practices, and OSHA's current enforcement authorities already provide mechanisms for addressing heat hazards without imposing additional federal mandates.

Critics also warn that prescriptive rest-break requirements and mandatory temperature-based triggers would be difficult to administer across varied workplaces. Multistate employers would face the burden of complying with overlapping federal, state, and local requirements.

Employer advocates have also questioned the use of fixed temperature thresholds. They argue that heat risk depends on multiple factors — including humidity, workload, clothing, acclimatization, and individual worker health — rather than temperature alone.

The political debate has also intensified in Congress. Opponents of OSHA's proposal have introduced legislation that would prohibit the agency from finalizing or enforcing certain prescriptive heat thresholds. Their position reflects broader concerns within parts of the business community that the proposed federal standard would expand regulatory burdens at a time when employers are already navigating labor shortages, rising costs, and increasing compliance requirements.