Crew leaders, farm labour contractors, and agronomy supervisors running field crews — cutting, harvesting, weeding, planting, packing — in open sun, often on piece rate, often on a crew that turns over between seasons.
Agriculture is the population this calculator was built around. The RSH-s protocol it defaults to (rest, shade, hydration, sanitation) came out of sugarcane work in Central America, where the combination of very heavy sustained workload, full solar exposure, and piece-rate pay produced the chronic kidney disease of non-traditional causes (CKDnt) epidemic that made occupational heat a measurable, not theoretical, harm.
Which heat rule applies to this crew, today? For a field crew the honest answer is usually "none that is enforceable, and one that is good" — outside a handful of US states and a few national rules, agricultural heat exposure is governed by voluntary guidance. Two consequences follow:
Legal status below is the registry's own legalStatus field for each rule. A "mandatory regulation" is enforceable law in its jurisdiction; everything else is guidance, a technical standard, or a proposal, and binds you only if your contract, your client, or your own programme adopts it.
Jurisdiction-neutral: these can set the schedule anywhere, because they claim no country.
| Rule | Authority | Legal status | What it sets |
|---|---|---|---|
| La Isla Network-informed RSH-s Default Protocol | La Isla Network / Adelante Initiative | Industry guidance — voluntary | Work/rest limits |
| NIOSH 2016-106 Table 6-2 | NIOSH | Guidance — voluntary | Work/rest limits |
| NIOSH REL/RAL Logarithmic Curve | NIOSH | Guidance — voluntary | Screening thresholds |
| ACGIH TLV / Action Limit | ACGIH | Technical standard — not law unless adopted or incorporated | Work/rest limits |
| ISO 7243:2017 WBGT Screening | ISO | Technical standard — not law unless adopted or incorporated | Screening thresholds |
Each binds only inside its own state.
| Rule | Authority | Legal status | What it sets |
|---|---|---|---|
| Colorado Agricultural Labor Conditions Rules (7 CCR 1103-15 Rule 3) | Colorado Department of Labor and Employment | Mandatory regulation | Control measures |
| Cal/OSHA Outdoor Heat Illness Prevention (Title 8 §3395) | California Division of Occupational Safety and Health | Mandatory regulation | Control measures |
| Oregon OSHA Heat Illness Prevention Standard (AO 3-2022) | Oregon Occupational Safety and Health Division (Oregon OSHA) | Mandatory regulation | Work/rest limits |
| Washington State DOSH Outdoor Heat Standard (WAC 296-62-095) | Washington State Department of Labor & Industries (L&I/DOSH) | Mandatory regulation | Work/rest limits |
| Maryland OSHA Heat Stress Standard (COMAR 09.12.32) | Maryland Occupational Safety and Health (MOSH) | Mandatory regulation | Work/rest limits |
| OSHA Heat National Emphasis Program (CPL 03-00-024, April 2026) | US OSHA, Directorate of Enforcement Programs | Guidance — voluntary | Alert levels |
A selection of national rules whose scope covers outdoor manual labour; see the country index for the full set.
| Rule | Authority | Legal status | What it sets |
|---|---|---|---|
| El Salvador Decreto No. 89 (TGBH) | El Salvador Ministry of Labour | Mandatory regulation | Work/rest limits |
| Nicaragua Resolución Ministerial sobre Higiene Industrial — Heat Stress (Chapter XV) | Ministerio del Trabajo (Nicaragua) | Mandatory regulation | Work/rest limits |
| Costa Rica Thermal Stress Prevention Rule (Decreto No. 39147-S-TSS) | Costa Rica Consejo de Salud Ocupacional (CSO) | Mandatory regulation | Work/rest limits |
| Mexico NOM-015-STPS-2001 (IBUTG) | STPS (Mexico Ministry of Labour) | Mandatory regulation | Screening thresholds |
| India WBGT Work/Rest Bands (unverified) | Bureau of Indian Standards | Superseded / historical — not current law | Work/rest limits |
| Kerala Seasonal Midday Outdoor-Work Rest Order (Minimum Wages Act, 1958, ss. 24-25) | Kerala Labour Commissionerate | Mandatory regulation | Stop-work / banned hours |
A cane-cutting crew starts at first light. By mid-morning the field WBGT is 30°C, the work is very heavy, and the crew is acclimatized after six weeks in the harvest. No country is declared, so only the jurisdiction-neutral protocols can bind — which is the realistic case for most of the world’s field agriculture.
Inputs: WBGT 30°C · very heavy work (520 W) · acclimatized worker · no worksite country declared
| Rule | What it returns at these inputs |
|---|---|
| La Isla Network-informed RSH-s Default Protocol | 15 / 45 min work/rest per hr |
| ACGIH TLV / Action Limit | 15 / 45 min work/rest per hr |
| NIOSH REL/RAL Logarithmic Curve | 25.5°C limit — exceeded |
| ISO 7243:2017 WBGT Screening | 25°C limit — exceeded |
Answer for this shift: 15 / 45 min work/rest per hr (most protective)
Every value above is computed at build time by the same engine the live calculator runs — the single most protective applicable result, never an average across standards. Change any input and the answer changes, which is what the calculator is for.
Screening-level guidance. This tool provides screening-level heat guidance for planning. It is a decision-support instrument, not a sole compliance authority or a medical prescription. Verify against the governing standard for your jurisdiction and consult a qualified professional for individual medical decisions.