Quick answer. There is no final federal OSHA heat standard as of November 2026. OSHA proposed one, Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings, on August 30, 2024; the hearing ended July 2, 2025, post-hearing comments closed October 30, 2025, and no final rule has been issued (OSHA rulemaking page). Until then OSHA cites heat under the general duty clause and inspects on hot days under its heat emphasis program (CPL 03-00-024). A written heat illness prevention plan is required by state rule in California (8 CCR §3395 outdoors, §3396 indoors), Oregon (OAR 437-002-0156), Maryland (COMAR 09.12.32) and Washington (WAC 296-62-09530, as part of the accident prevention program).
Where the rules stand
- Federal: no standard yet. OSHA published a proposed rule, Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings, on August 30, 2024. Comments closed in January 2025, the public hearing ran June 16 to July 2, 2025, and post-hearing comments closed October 30, 2025. As of this writing there is no final rule and no announced date for one.
- Federal: the general duty clause. Until there is a standard, OSHA cites heat under section 5(a)(1) of the OSH Act: a recognized hazard likely to cause death or serious harm, with a feasible way to fix it. Heat deaths get cited this way every summer, and the citation reads like a list of what a plan should have had: water, rest, shade, acclimatization, training, a way to get help.
- Federal: the emphasis program. A new National Emphasis Program on heat (CPL 03-00-024) took effect April 10, 2026 and runs five years. On "heat priority days," any day the heat index reaches 80°F, inspectors opening an inspection for any other reason ask whether you have a heat program and check it. OSHA also schedules heat inspections on days with a National Weather Service heat advisory, and the target list covers 55 industries including construction, landscaping, trucking, warehousing and most manufacturing.
- States with their own rules: California (outdoor since 2005, indoor since July 2024), Washington (outdoor, year-round), Oregon (indoor and outdoor), Maryland (indoor and outdoor, since September 2024), Minnesota (indoor, by wet-bulb globe temperature), Nevada (a written heat hazard analysis for employers with more than 10 employees, since late 2024), and Colorado for agriculture. If you work in one of these, the state rule is the floor, and the numbers below are mostly theirs.
If you are waiting for the final rule before writing a plan, you are already behind. The proposed rule is the clearest statement there is of what OSHA thinks a reasonable employer does, and inspectors are already measuring against it under the general duty clause.
Texas. Texas is a federal-OSHA state with no heat rule of its own, so what applies on a Texas jobsite or plant floor is the general duty clause, the national emphasis program (CPL 03-00-024) and OSHA's heat guidance. On a heat-advisory day the Dallas, Fort Worth, Houston, Austin, San Antonio, El Paso, Corpus Christi and Lubbock area offices can open an inspection at any outdoor site they pass, and the first things asked for are the written plan, the acclimatization schedule and the training record. The free consultation program, OSHCON, will review a heat plan without a citation.
The numbers: 80 and 90
Almost every rule, proposed or state, uses the same two lines. Write them into your plan and the crew will know what day it is.
| Trigger | What starts | Where it comes from |
|---|---|---|
| Heat index 80°F | The plan is on: water within reach, a shaded or cooled rest area, breaks allowed whenever needed, new and returning workers watched, someone checking the forecast. | OSHA's proposed rule and NEP; Oregon and Maryland. Washington's outdoor rule (air temperature at or above 80°F, 52°F in nonbreathable clothing) and California's shade rule (air temperature above 80°F) |
| Heat index 90°F | High-heat procedures: scheduled rest breaks (the proposed federal rule says 15 minutes every two hours, paid), a buddy system or a supervisor watching each worker, and a hazard alert at the start of the shift. | OSHA's proposed rule; Oregon. Washington at an air temperature of 90°F (WAC 296-62-09547: 10-minute cool-down every 2 hours, 15 minutes every hour at 100°F) |
| Air temperature 95°F | California's high-heat procedures for construction, agriculture, landscaping, oil and gas, and hauling of agricultural and construction materials: pre-shift meeting, effective observation, and reminders to drink. | 8 CCR §3395(e) |
| Indoor 82°F / 87°F | California's indoor rule starts at 82°F and requires measurement and controls at 87°F, or at 82°F with heavy clothing or radiant heat. | 8 CCR §3396 |
Heat index is temperature plus humidity, measured in the shade. The National Weather Service notes that full sun can add up to 15°F. A crew in the sun on a pavement at a reported heat index of 88 is working above 100. Use the NIOSH heat app or a wet-bulb globe thermometer on site rather than the airport's number.
The eight parts of the plan
- Who is in charge. Name the heat coordinator by role: the foreman on each crew, the shift lead in the plant. They watch the forecast, call the trigger, and have the authority to change the schedule and stop work. The proposed federal rule calls this person the heat safety coordinator.
- How you know what day it is. Where the temperature comes from (a thermometer on site, the NIOSH app, the NWS forecast), who checks it, and when. In California indoors you have to measure and record it when the rule is triggered.
- Water. One quart per worker per hour for the whole shift, cool, free, and close enough that nobody has to leave the work to get it. Coolers restocked by name. The crew is told to drink a cup every 15 to 20 minutes, before they are thirsty. Electrolyte drinks are a supplement, not a replacement.
- Shade and rest. A place out of the sun, or cooled, big enough for everyone on break at once, close to the work. A running truck with the AC on counts for a crew; a closed truck in the sun does not. Breaks are allowed any time a worker needs one, no questions, no pay cut.
- Acclimatization. The schedule for new workers and anyone back from a week or more away, and the plan for the first heat wave of the year. See the next section. This is the part that saves lives, and it is the part most plans skip.
- High-heat procedures. At the 90°F line: the scheduled rest cycle, the buddy system, the pre-shift talk that says it is a high-heat day, the heavy work moved to the morning, more frequent checks on anyone in a respirator or chemical suit.
- Training. Everyone before the first day in the heat and every year: risk factors, the water and rest rules, acclimatization, the symptoms of exhaustion and stroke, what to do, who to call, and that reporting symptoms is expected. Supervisors get the extra part: watching the forecast, the triggers, the emergency response. In the language the crew understands.
- Emergency response. The site address for 911 in the foreman's phone. Who calls, who stays with the worker, who meets the ambulance. How you cool someone right now: shade, water on the skin, ice packs, a tub or a tarp with water and ice if you have one. Nobody with symptoms is left alone or sent home to sleep it off.
Write it down. The proposed federal rule would require a written plan for employers with more than 10 employees; California, Oregon, Washington and Maryland require one of every employer their rules cover; and the general duty clause citation asks what you had. One page per crew with the names filled in beats twenty pages nobody opened.
Acclimatization: the first week
OSHA's own figure is that nearly three out of four heat deaths happen in a worker's first week on the job, most of them in the first few days. The body takes one to two weeks to adapt to heat, and loses the adaptation after a week away. The fix is cheap and written down by NIOSH:
- New workers: 20% of the normal heat exposure the first day, then 20% more each day, full exposure on day five. "Exposure" is time in the heat doing the work, not time on site.
- Experienced workers back from a week or more away: 50% the first day, 60% the second, 80% the third, full the fourth.
- The first heat wave of the season, any day that is 10°F or more above the recent average, is treated like a return: everybody is watched, the heavy work is shortened, breaks are more frequent.
Temps, new hires, workers transferred from the office or the night shift, and workers coming back from vacation or an injury all count as new. The proposed federal rule and the California, Oregon and Maryland rules all require some version of this schedule; the exact option you pick matters less than actually doing it for every new name on the crew list.
Symptoms and what to do
| Condition | What you see | What to do |
|---|---|---|
| Heat rash | Red bumps on neck, chest, folds of skin | Cooler, drier conditions. Keep the area dry. Not an emergency, but a sign the heat is getting to them. |
| Heat cramps | Muscle cramps in legs, arms, abdomen, usually with heavy sweating | Rest in the shade, water with food or an electrolyte drink. Medical attention if cramps last more than an hour or the worker has heart problems. |
| Heat exhaustion | Heavy sweating, weakness, dizziness, headache, nausea, cool and clammy skin, fast weak pulse, irritability | Stop work. Shade, cool water to drink, loosen clothing, cool the skin with water and a fan. Someone stays with them. If no better in 15 minutes, or vomiting, or confusion: 911. |
| Heat stroke | Confusion, slurred speech, strange behavior, seizures, passing out, hot skin (dry or sweating), body temperature over 104°F | 911 first. Then cool them as fast as you can: shade, water over the whole body, ice packs at neck, armpits and groin, a tub or tarp of water and ice if available, fan them. Keep cooling until the ambulance takes over. Do not give fluids to someone who is confused or unconscious. |
The line between exhaustion and stroke is the brain. A worker who is confused, acting strange or passing out has a stroke until proven otherwise, and every minute before cooling starts matters more than anything else you do. Cool first, transport second.
Indoor heat
Kitchens, laundries, warehouses without air conditioning, foundries, body shops in August, a plant with ovens and a metal roof: the same physiology and, in California, Oregon, Maryland and Minnesota, a rule. The proposed federal rule covers indoor work areas too. The plan is the same eight parts with two changes: engineering controls come first (fans below about 95°F, ventilation, exhausting the hot process, spot cooling, reflective barriers, air conditioning in a break room), and the measurement has to happen inside, at the work station, not at the loading door. California requires the readings to be recorded and kept.
Mistakes that show up in the fatality reports
- The new guy on his second day doing the same work as the ten-year hand, in July.
- Water in the truck, 200 yards from the work, and a crew paid by the piece.
- "Take breaks when you need them" with a schedule that punishes anyone who does.
- A worker who "went to sit in the truck" and was found an hour later.
- A sick worker driven home instead of cooled and watched.
- The foreman's phone with no site address for 911 on a rural job.
- Heat training in English for a crew that works in Spanish.
- Respirators, Tyvek suits and welding leathers with no adjustment to the work-rest cycle.
- A plan for the outdoor crews and nothing for the shop.
A heat plan with the triggers filled in, and a daily heat check for the foreman
29Safety's written heat illness prevention program comes with the federal and state triggers already in it, a daily heat check the foreman does from the phone when the forecast crosses 80°F, the acclimatization schedule for each new worker, and the heat training with a record for every person, in English and Spanish.
See exactly what you'd get
The JHA plus a toolbox talk record, an inspection and more, in one PDF: five documents for a jobsite crew, or three for a plant. No watermark.
Plans from $199 a month. No per-person fees. 14 days free.
Rather have us write it? Two written programs ($295)
Questions we get
Is there an OSHA heat standard?
Not a federal one, as of November 2026. OSHA proposed a standard in August 2024 and held hearings in 2025, but has not issued a final rule. Federal OSHA cites heat hazards under the general duty clause and runs a National Emphasis Program on heat. California, Washington, Oregon, Maryland, Minnesota, Nevada and Colorado have state rules.
At what temperature do the heat rules kick in?
A heat index of 80°F is the common starting line in OSHA's proposed rule, its emphasis program, and the Oregon and Maryland rules. Washington's outdoor rule starts at an air temperature of 80°F (52°F for workers in nonbreathable clothing), and California's outdoor shade requirement at an air temperature above 80°F. High-heat procedures start at a heat index of 90°F in the federal proposal and in Oregon, at an air temperature of 90°F in Washington, and at 95°F air temperature in California for construction and several other industries.
How much water do I have to provide?
The standard across the state rules and OSHA's proposal is one quart per worker per hour for the full shift, cool, free, and close to the work. Encourage a cup every 15 to 20 minutes.
Are paid rest breaks required in the heat?
In California, Oregon, Washington and Maryland, yes: preventive cool-down rests are paid, and Oregon requires scheduled breaks at a heat index of 90°F. OSHA's proposed federal rule would require a paid 15-minute break every two hours at that level. Under the general duty clause today, a crew that is not allowed to rest in the heat is the kind of thing OSHA cites.
Do I need a written heat plan?
In California, Oregon, Washington and Maryland, yes, for every employer the state rule covers. OSHA's proposed rule would require one for employers with more than 10 employees. Everywhere else it is not required by name, but a general duty clause citation after a heat illness asks what program you had, and a one-page written plan is the answer.
Does this apply to indoor work?
Yes where there is a rule: California's §3396 starts at 82°F indoors, and Oregon, Maryland and Minnesota cover indoor heat. OSHA's proposed rule covers indoor work areas, and the general duty clause already does. The same eight parts apply, with engineering controls like ventilation and spot cooling first.
What is a heat injury and illness prevention plan?
It is the name OSHA's proposed rule uses for a heat plan, the HIIPP. The proposal would require employers to develop and implement a plan for each work site, in writing if the employer has more than 10 employees, naming a heat safety coordinator, with procedures at an initial trigger of a heat index of 80°F and a high heat trigger of 90°F, including a paid 15-minute rest break at least every two hours at the high trigger. It is a proposal, not a rule. A heat illness prevention plan, a heat protection plan and a heat illness prevention program are the same kind of document.
Is there a sample heat illness prevention plan?
Yes, at the top of this page: a filled-out heat illness prevention plan for a utility crew, in English and Spanish, and the foreman's daily heat check for a July day. It follows the eight parts above. Use it as a model and fill in your own crews, water, shade and emergency details; in California the plan has to be in English and in the language most of your employees understand (8 CCR §3395(i), §3396(i)).
Not sure how this applies to your work? in the chat, or email safetyteam@29safety.com.