State Heat Illness Prevention Standards — Temperature Triggers and Required Employer Actions
At what outdoor temperature must employers provide shade, water, rest breaks, and written prevention plans? Six U.S. states enforce specific heat illness prevention standards with temperature triggers that exceed the stalled federal OSHA proposal. This dataset compares each state's trigger temperatures, required actions at each tier, coverage scope (indoor/outdoor, which industries), acclimatization requirements, and regulatory citations.
Records7
Sources6
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The data
| regulation citation | jurisdiction | effective date | initial trigger temperature f | initial trigger actions | high heat trigger temperature f | high heat actions | coverage scope | acclimatization period days | written plan required |
|---|---|---|---|---|---|---|---|---|---|
| 7 CCR 1103-15 (Agricultural Labor Conditions Rules) | Colorado | January 1, 2026 | 80 | Provide adequate shade within 0.25 miles; provide 32 ounces of cool potable water per employee per hour kept at 60°F or cooler; allow additional preventative cool-down rest of at least 10 minutes in shade when employee believes necessary | 95 | Increased risk conditions: employees must not perform more than 2 hours of work before at least 10 minutes of rest; employer must notify employees of heat protection rights before shift; provide fans in employer-provided housing sleeping quarters | Agricultural employment only; indoor and outdoor; increased risk conditions also triggered by unhealthy air quality, workday over 12 hours, heavy clothing/PPE, or first 4 days of work | 4 | Yes |
| Cal. Code Regs. tit. 8, § 3395 | California | May 1, 2015 | 80 | Shade shall be present when the temperature exceeds 80 degrees Fahrenheit; access to potable drinking water (one quart per employee per hour); employees allowed and encouraged to take a preventative cool-down rest in the shade (not less than 5 minutes) | 95 | Effective communication maintained; observation of employees for alertness and signs or symptoms of heat illness (supervisor observation of 20 or fewer, mandatory buddy system, or regular communication); designated employee authorized to call for emergency medical services; reminders to drink water throughout shift; pre-shift meetings to review high heat procedures; for agriculture: minimum ten minute net preventative cool-down rest period every two hours | Outdoor only; all outdoor places of employment for basic provisions; agriculture, construction, landscaping, oil and gas extraction, and transportation or delivery of heavy materials for high-heat procedures | 14 | Yes |
| COMAR 09.12.32 | Maryland | September 30, 2024 | 80 | Provide shaded areas as close to work area as practicable, open to air on at least three sides; provide cool potable drinking water; allow preventative cool-down rest periods | 90 | Minimum rest period of 10 minutes for every 2 hours worked at heat index above 90°F and below 100°F; minimum rest period of 15 minutes for every hour worked at heat index above 100°F; monitor exposed employees via phone, radio, buddy system, or other effective observation; rest periods taken in shade | Indoor and outdoor; all industries where heat index equals or exceeds 80°F; exempt: emergency operations and essential services, incidental exposure under 15 consecutive min/hr, mechanically ventilated buildings/vehicles below 80°F | 14 | Yes |
| General Duty Clause, Section 5(a)(1) of the Occupational Safety and Health Act of 1970 | Federal OSHA | 1970 | None specified | Employers are required to provide their employees with a place of employment that is free from recognized hazards that are causing or likely to cause death or serious harm to employees, including heat-related hazards | None specified | No specific high-heat procedures mandated at federal level; enforcement relies on the General Duty Clause | All workplaces covered by OSHA; no heat-specific standard finalized | None specified | No heat-specific plan required |
| OAR 437-002-0156 | Oregon | June 15, 2022 | 80 | Shade when heat index equals or exceeds 80°F; drinking water up to 32 ounces per hour; encourage and allow preventative cool-down rest periods | 90 | Mandatory rest break schedule: at heat index 90°F or greater, minimum 10 minutes every 2 hours; at 100°F or greater, 15 minutes every hour (Table 1 minimum). Simplified schedule option (Table 2): 90°F 10 min/2hr, 95°F 20 min/hr, 100°F 30 min/hr, 105°F 40 min/hr. Communication by voice or electronic means; buddy system or regular communication for lone workers; designated employee authorized to call for emergency medical services | Indoor and outdoor; all industries where heat index equals or exceeds 80°F; exempt: incidental exposure under 15 min/hr, heat from work process, emergency operations, mechanically ventilated buildings below 80°F | 14 | Yes |
| WAC 296-62-095 through 296-62-09560 | Washington | July 17, 2023 | 80 | Address outdoor heat exposure safety program in written accident prevention program; provide sufficiently cool drinking water; provide shade or other sufficient means to reduce body temperature; encourage and allow preventative cool-down rest periods | 90 | Mandatory cool-down rest periods: at or above 90°F, 10 minutes every 2 hours; at or above 100°F, 15 minutes every 1 hour; closely observe employees for signs and symptoms via regular communication, mandatory buddy system, or other effective means | Outdoor work; all industries | 14 | Yes |
| WAC 296-62-09530 (nonbreathable PPE) | Washington | July 17, 2023 | 52 | Same outdoor heat exposure safety program requirements: drinking water, shade or other means to reduce body temperature, preventative cool-down rest periods, acclimatization, emergency response procedures | 90 | Mandatory cool-down rest periods: at or above 90°F, 10 minutes every 2 hours; at or above 100°F, 15 minutes every 1 hour; close observation via buddy system, regular communication, or other effective means | Outdoor work; employees required to wear nonbreathable clothes including vapor barrier clothing or PPE such as chemical resistant suits | 14 | Yes |
Where this came from
Every record above links the page it was taken from and quotes the sentence that states it. These are the 6 sources this dataset was assembled from.
- cdle.colorado.govhttps://cdle.colorado.gov/sites/cdle/files/info_%2312c_heat_protection%3B_short-handled_tool_%26_hand-weeding_thinning_limits%3B_public_health_emergency_protections_1.27.2026.pdf
- dir.ca.govhttps://www.dir.ca.gov/title8/3395.html
- regs.maryland.govhttps://regs.maryland.gov/us/md/exec/comar/09.12.32.02
- osha.govhttps://www.osha.gov/heat-exposure/standards
- osha.oregon.govhttps://osha.oregon.gov/OSHARules/div2/div2J.pdf
- app.leg.wa.govhttps://app.leg.wa.gov/wac/default.aspx?cite=296-62-09530
Machine-readable
- data.jsonThe whole dataset — every record with its source URL and source quote.
- Open Knowledge Format bundleOne JSON object per line — every record's frontmatter and quoted span exactly as it is held here, in one fetch.
- data.csvThe same records as one flat table, for a spreadsheet or a dataframe. The last four columns are the source URL, the quoted sentence it was read from, the date we last checked it, and which columns are our reading rather than the page's words.
- How this is made and checkedWhat "verified against source" does and does not mean.
From your own code
Same records, same quotes, without scraping the page: refsource is on PyPI and npm. Each value comes back carrying the URL it was read from and the sentence on that page that states it — .source and .quote sit on the value itself rather than in a side channel, so the checking step is available instead of skipped.
pip install refsource
refsource lookup state-heat-illness-prevention-standards jurisdiction=Colorado
npx -y refsource lookup state-heat-illness-prevention-standards jurisdiction=ColoradoSet your AI assistant up to use this
Two files and no account. Put this in .mcp.json at the root of your project — Claude Code, Cursor, Windsurf, VS Code and Codex all read that file — and your assistant can look this dataset up instead of recalling it. The server is remote, keyless and read-only.
{
"mcpServers": {
"referencesource": {
"type": "http",
"url": "https://referencesource.org/mcp"
}
}
}Add to Cursor · or, on the command line: claude mcp add --transport http referencesource https://referencesource.org/mcp --scope project
Then one line in the project's CLAUDE.md or AGENTS.md, so the assistant knows when to reach for it:
When a question needs "State Heat Illness Prevention Standards — Temperature Triggers and Required Employer Actions", call the referencesource MCP server at https://referencesource.org/mcp (tool `search_records`, dataset_slug `state-heat-illness-prevention-standards`) instead of answering from memory — every record it returns carries its source URL and a verbatim quote from that page.What each tool does, and the servers built over single registers: Connect your AI assistant.