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Occupational Heat Stress Rules — United States (federal)

Standards

StandardAuthorityLegal statusRule type
Cal/OSHA Indoor Heat Illness Prevention (Title 8 §3396)California Division of Occupational Safety and HealthRegulationControl Overlay
OSHA Federal Heat Rule NPRM (Proposed)US OSHAProposed RuleControl Overlay
CPWR / OSHA-CPWR Construction Heat OverlayCPWR / OSHA-CPWR AllianceIndustry GuidanceControl Overlay
MSHA Mining Heat Stress OverlayMine Safety and Health AdministrationGuidanceControl Overlay
NFL / American Football Heat Practice OverlayGeorgia High School Association By-Law 2.67 WBGT heat policy (reproduced in an NFL-hosted Korey Stringer Institute presentation)Industry GuidanceAlert Overlay
Washington State DOSH Outdoor Heat Standard (WAC 296-62-095)Washington State Department of Labor & Industries (L&I/DOSH)RegulationSchedule Engine
Oregon OSHA Heat Illness Prevention Standard (AO 3-2022)Oregon Occupational Safety and Health Division (Oregon OSHA)RegulationSchedule Engine
Maryland OSHA Heat Stress Standard (COMAR 09.12.32)Maryland Occupational Safety and Health (MOSH)RegulationSchedule Engine
Minnesota OSHA Indoor Ventilation and Temperature Rule (5205.0110)Minnesota OSHARegulationSchedule Engine
US Navy / Marine Corps Ashore Flag ConditionsNavy Bureau of Medicine and Surgery (BUMED)Technical StandardSchedule Engine
Cal/OSHA Outdoor Heat Illness Prevention (Title 8 §3395)California Division of Occupational Safety and HealthRegulationControl Overlay
Colorado Agricultural Labor Conditions Rules (7 CCR 1103-15 Rule 3)Colorado Department of Labor and EmploymentRegulationControl Overlay
Nevada OSHA Heat Illness Prevention Regulation (R131-24)Nevada OSHA / Nevada Division of Industrial RelationsRegulationControl Overlay
NYC Executive Order No. 17 — Outdoor Worker Heat ProtectionOffice of the Mayor of New York CityRegulationControl Overlay
San Antonio Contractor Outdoor Heat OrdinanceCity of San AntonioRegulationControl Overlay
Cal/OSHA Protection from Wildfire Smoke (Title 8 §5141.1)California Division of Occupational Safety and HealthRegulationSmoke Overlay
Oregon OSHA Protection from Wildfire Smoke (OAR 437-002-1081)Oregon Occupational Safety and Health Division (Oregon OSHA)RegulationSmoke Overlay
Washington L&I / DOSH Wildfire Smoke Rule (WAC 296-820)Washington State Department of Labor & Industries (L&I/DOSH)RegulationSmoke Overlay

Most protective composite

Reference conditions: moderate work (300 W), acclimatized worker. WBGT values below are illustrative reference points, not a threshold of any single standard.

WBGT (°C)Most protective result
2860 / 0 min work/rest per hr (most protective)
3145 / 15 min work/rest per hr (most protective)
34Stop work — At least one applicable standard requires stop work or prohibits continued work.

This is the single most protective applicable result at each condition (stop-work override, else minimum work / maximum rest minutes) — standards are never averaged. Contributing standard(s) across these conditions: US Navy / Marine Corps Ashore Flag Conditions.

Wildfire smoke

Wildfire-smoke overlays are excluded from the composite above and are never averaged with WBGT-based standards — see wildfire smoke guidance.

Sources