Heat Illness Rules by State
Heat is the leading weather-related killer of U.S. workers, but there’s no final federal heat standard. A handful of states have written their own rules. Where you work decides whether your employer must follow specific heat rules, or only the general duty to protect you.
- Construction
- General Industry
- Agriculture
- Arizona
- California
- Colorado
- Florida
- Maryland
- Minnesota
- Nevada
- Oregon
- Texas
- Washington
Photo: shade canopy, water cooler and rest area set up on a summer jobsite
States with heat standards
| State | Rule | Covers | Key triggers |
|---|---|---|---|
| California | T8 §3395 (outdoor), §3396 (indoor) | All outdoor workplaces; indoor workplaces | Outdoor shade at 80°F, high-heat procedures at 95°F; indoor rules start at 82°F |
| Washington | WAC 296-62-095 | Outdoor work | Starts at set temperatures (lower for workers in non-breathable clothing), with more rest breaks in high heat |
| Oregon | OAR 437-002-0156, 437-004-1131 | Indoor and outdoor work, including agriculture | Heat index 80°F; more protections at 90°F |
| Maryland | COMAR 09.12.32 | Indoor and outdoor work | Heat index 80°F; scheduled rest breaks from 90°F |
| Nevada | Regulation R131-24 | Employers with more than 10 employees | Job hazard analysis; written plan where heat hazards exist |
| Minnesota | Minn. R. 5205.0110 | Indoor workplaces | Heat stress limits based on how hard the work is |
| Colorado | Agricultural labor rules | Farm workers | Shade at 80°F; extra rest breaks in high heat |
Other states are working on rules or guidance. For example, Arizona runs a heat emphasis program and has employer heat guidance. Rules change quickly, so check your state agency for the latest.
What most heat rules require
- Enough cool, fresh drinking water, close to the work, for every worker to drink about a quart an hour
- Shade or a cool-down area big enough for the workers on break
- Rest breaks to cool down, and more of them as it gets hotter
- Acclimatization: easing new and returning workers into the heat over the first days
- A written heat illness prevention plan
- Training for workers and supervisors on symptoms and first aid
- Watching workers closely in high heat, and an emergency plan to get help fast
If your state has no heat rule
- The General Duty Clause still applies. Federal OSHA and state plans can cite employers for serious heat hazards. Federal OSHA has run a heat emphasis program since 2022.
- A federal heat standard has been proposed. OSHA published a proposed heat injury and illness prevention rule in 2024 and held hearings in 2025. It isn’t in effect; check OSHA for its status.
- Some states block local rules. Texas (2023) and Florida (2024) passed laws that stop cities and counties from requiring their own heat protections, such as mandatory water breaks. Federal OSHA rules still apply there.
Heat stroke is an emergency. Confusion, slurred speech, fainting or hot skin means call 911 and cool the worker right away with cold water or ice. See Heat Illness Prevention.
Standards & references
Last updated: