What regulations cover heat illness for workers in the United States?

Currently there is no federal OSHA standard specifically regulating workplace heat illness, though OSHA published a proposed rule in August 2024 that would become the first federal heat standard. Until a federal standard is finalized, OSHA enforces heat safety through the General Duty Clause of the Occupational Safety and Health Act, which requires employers to provide workplaces free from recognized hazards causing or likely to cause death or serious harm.

The proposed federal rule would require employers to create heat injury and illness prevention plans, monitor temperatures, provide water and rest breaks, implement acclimatization programs for new workers, and train employees when the heat index reaches 80°F or higher. Additional protections would trigger at a "high heat" threshold requiring more frequent rest breaks and closer worker observation.

Five states have enacted heat illness prevention standards: California, Oregon, Washington, Colorado, and Minnesota. California's standard requires employers to provide water, shade, training, and written prevention plans when outdoor temperatures reach 80°F, with additional protections at 95°F. Oregon's rules apply to both indoor and outdoor work when the heat index reaches 80°F, requiring shade access, drinking water up to 32 ounces per hour, written prevention plans, and mandatory rest breaks at 90°F or higher. Washington requires similar protections for outdoor workers at 80°F ambient temperature, with enhanced requirements including mandatory rest break schedules when temperatures reach 90°F.

OSHA requires employers to provide potable water under sanitation standards and to report heat-related worker deaths within eight hours and hospitalizations within 24 hours. Workers experiencing heat illness symptoms have the right to rest breaks and medical attention, and employers cannot retaliate against workers who report unsafe heat conditions.