The OSHA Heat National Emphasis Program is an internal instruction to OSHA's own compliance officers, not an employer duty. It changes OSHA's inspection posture at a forecast heat index of 80°F and when the National Weather Service has a heat warning or advisory in effect for the local area. It creates no exposure limit, no work/rest schedule and no stop-work, and it never contributes to the calculator's composite recommendation.
No standalone formula is published for this standard; see programmable logic and parameters below.
Governing metric: Forecast heat index (°F) and the active National Weather Service heat alert for the local area
| Parameter | Value |
|---|---|
heatPriorityDayHeatIndexF | 80 |
heatSafetyToolWarningMinF | 80 |
heatSafetyToolDangerMinF | 95 |
effectiveDate | "2026-04-10" |
operativeUntilNoLaterThan | "2031-04-10" |
targetIndustryNaicsCount | 55 |
Version history matters here, which is why the engine id carries no year. The April 8 2022 NEP is cancelled: every page of its PDF is watermarked 'OSHA ARCHIVE DOCUMENT' and its landing page sits under 'Directives (Archived)'. The chain, all four links read in primary text: the 2022 NEP carried a 3-year ceiling expiring 2025-04-08; CPL 03-01-024 (effective 2025-01-16) extended it to 2026-04-08; it then lapsed for about two days; the reissue took effect 2026-04-10 with a 5-year ceiling. DELIBERATELY NOT ENCODED: the 2022 text's separate four-category NWS heat-index table (Caution 80-90°F, Extreme Caution 91-103°F, Danger 103-124°F, Extreme Danger 126°F and above) and the 2022 Appendix G numbers (100/105/95/90/75°F), all deleted by the reissue under its own sec. VIII.B. The four-category table also contradicted the Heat Safety Tool bands printed two paragraphs away in the same 2022 document, putting Danger at 103°F where the bands put it at 95°F; only the 80/95°F bands the 2026 directive retains and restates twice are encoded. Also not encoded: the 104°F figure, which defines exertional heat stroke physiologically rather than setting an environmental trigger, and the 'cup of water every 15 minutes' instruction, which governs compliance-officer self-protection under Appendix B and is not worker guidance. The directive states no rounding rule for a non-integer heat index between the integer band edges — 94°F is expressly inside Warning, stated twice, so only the open interval 94.1-94.9°F is undefined; treating 95°F and above as Danger is this calculator's implementation choice and is labelled as such. This engine is always excluded from getMostProtective: a 95°F 'Danger' label is a communication tier, and letting an inspection-targeting number act as a protective ceiling is the conflation the project's domain rules forbid.
Programmable logic: A forecast heat index at or above 80°F makes a heat-priority day, on which the Area Office will assess indoor and outdoor heat hazards or provide worksite assistance, and compliance officers conducting an inspection for any other reason should inquire into heat-illness prevention. The OSHA-NIOSH Heat Safety Tool communication bands are surfaced as informational labels only: caution below 80°F, warning 80-94°F, danger at or above 95°F. An active NWS heat warning or advisory for the local area makes programmed inspections of the targeted high-hazard industries available; an Extreme Heat Watch does not, and an unknown alert state propagates as null rather than false because asserting 'no alert' would be the wrong default for a safety overlay. The engine never produces work/rest minutes, a ceiling or a stop-work, and always carries the caveat that OSHA itself records heat fatalities below 80°F.
Required inputs: heatIndexF
Optional inputs: nwsHeatAlert