California Heat Wave: Cal/OSHA Rules and AB 2243 Draft

Southern California is in the middle of an October heat wave, and Cal/OSHA is reminding employers that the heat illness rules still apply in the fall. On October 2, 2026, Cal/OSHA said an extreme heat warning would be in effect for the Los Angeles and San Diego regions, including inland Orange County, from Friday, October 2 at 10 a.m. until Thursday, October 8 at 8 p.m., with daytime temperatures from the mid-90s on the coast to as high as 107 in the valleys. It also flagged heat advisories for parts of Northern California and the San Joaquin and Sacramento valleys.

That makes this a good week to check two things: whether your current heat program is actually working in the field, and whether it is ready for the changes Cal/OSHA has floated in its latest AB 2243 discussion draft.

This post is a plain-language summary, not legal advice. Read the current Title 8 sections and the draft itself before you change practice.

What applies right now

These are the rules in effect today, as Cal/OSHA summarized them in its October 2 release.

Outdoor work (Title 8 § 3395): employers must provide fresh water, access to shade (which must be in place when temperatures exceed 80 degrees), and cool-down rest breaks whenever a worker requests one, in addition to regular breaks. When outdoor temperatures reach or exceed 95 degrees, additional high-heat procedures apply in specific industries: agriculture, construction, landscaping, oil and gas extraction, and transportation or delivery of agricultural products, construction materials, or other heavy materials.

Indoor work (Title 8 § 3396): the indoor standard applies to most indoor workplaces, such as restaurants, warehouses, and manufacturing facilities. When an indoor work area reaches 82 degrees, employers must take steps to protect workers, including water, rest, cool-down areas, and training.

Both settings: employers need a written heat illness prevention plan and effective training so supervisors and workers can recognize the signs and symptoms of heat illness and know what to do in an emergency. If you have people working both indoors and outdoors, both standards can apply.

What the August 14, 2026 AB 2243 draft would change

Assembly Bill 2243 (2022) directed Cal/OSHA to revisit the heat standards. On August 14, 2026, Cal/OSHA posted a further revised discussion draft of §§ 3395 and 3396 and took comments through September 21, 2026. The draft marks proposed additions with underlining and proposed deletions with strikeout. Here are the changes most likely to matter for construction, manufacturing, and other SMB employers.

1. High-heat procedures for every outdoor employer

The draft strikes the industry list in § 3395(a)(2) and the exception that currently lets employers outside those industries skip the high-heat procedures in subsection (e). If that survives, the 95 degree high-heat procedures would apply to all outdoor places of employment, not just agriculture, construction, landscaping, oil and gas, and heavy-materials transportation. Think utilities, outdoor retail and yard operations, facilities and grounds crews, outdoor events, and similar work.

2. A new acclimatization trigger, and returning workers count too

Today's outdoor rule requires close observation for 14 days when an employee is newly assigned to a "high heat area." The draft replaces that with a clearer trigger: when a newly assigned employee, or an employee returning after an absence of more than 14 days, is assigned to a location where the predicted high for the day will be at least 80 degrees.

For indoor work, the draft triggers the same acclimatization duties when a new or returning employee is assigned to a location where the temperature reaches 82 degrees or the heat index reaches 87 degrees.

In either setting, the employee would be closely observed by a supervisor or designee for the first 14 days, and the employer would choose one of two options:

• Option 1: pre-shift meetings on close-observation days to review acclimatization and close-observation procedures, first aid and emergency response, drinking water, and the right to take a cool-down rest.
• Option 2: a graduated heat exposure schedule. New employees would be limited to no more than 20%, 40%, 60%, and 80% of the usual work duration on days one through four. Returning employees would be limited to 50%, 60%, and 80% on days one through three.

The draft would require Option 2 for law enforcement, firefighting, and emergency response personnel during high-intensity training. It also includes an exception if the employer can show the employee consistently worked under similar conditions for the prior 14 days.

3. "Closely observe" gets a definition

The draft defines "closely observe" as effectively monitoring an employee to detect early signs of heat illness and trigger a prompt response. That includes frequent visual observation and frequent two-way verbal communication for onsite workers, and frequent two-way communication for remote workers, enough to catch early signs such as fatigue, shortness of breath, irritability, confusion, disorientation, odd behavior, and personality changes. If your current approach is a supervisor glancing across the site, this definition asks for more.

4. Broader definitions of heat illness and its signs

The draft adds rhabdomyolysis to the definition of heat illness, spells out signs and symptoms for heat cramps, heat exhaustion, rhabdomyolysis, heat syncope, and heat stroke, and moves the heat wave definition into the definitions section. It also adds supplements and recreational drugs to the list of personal risk factors.

5. Training in a language and literacy level workers understand

The draft adds that heat training must be provided in a language and at a literacy level each employee understands, and that employers must give employees a chance to ask questions about the training materials.

6. The written plan has to actually reach workers

Under the draft, the heat illness prevention plan would be distributed to new employees at hire, during heat illness training, and to every employee at least once a year, with no requirement to distribute it to an employee more than twice a year. Instead of physical copies, an employer could post the plan online in English in a format that can easily be translated into other languages.

7. Orders to Take Special Action, including wearables

A new subsection (j) would let Cal/OSHA, under Title 8 § 332.3, order an employer to take additional heat illness prevention steps through an Order to Take Special Action. The draft says those steps may include wearable technology that monitors physiological responses to heat stress, with the employer responsible for keeping that health data secure and not using it to discriminate against employees.

8. Agriculture cool-down timing

For agriculture at 95 degrees or above, the draft clarifies that the required ten-minute preventative cool-down rest every two hours is in addition to the time needed to reach shade.

Where this stands

This is still a discussion draft. Cal/OSHA's AB 2243 page lists the August 14, 2026 draft for comment with a September 21, 2026 deadline, and that window has closed. Any of this could change before Cal/OSHA sends a proposal to the Occupational Safety and Health Standards Board, which would then run its own formal rulemaking with public notice and a hearing. As of October 6, 2026, we did not find a heat illness item on the Standards Board's October 15, 2026 meeting agenda.

What to do this week

1. Confirm your field basics for the current heat wave: water, shade up at 80 degrees outdoors, cool-down areas indoors at 82 degrees, and 95 degree high-heat procedures where you are in a covered industry.
2. Check who is new or returning from more than two weeks away, and make sure a named supervisor is closely observing them. That is good practice now and a likely future requirement.
3. Pull your written heat illness prevention plan and ask a simple question: would a new hire actually get a copy, in a language they read?
4. If you run outdoor crews outside the currently listed industries, sketch what 95 degree high-heat procedures would look like for them (pre-shift meetings, observation, communication) so you are not starting from zero if the draft holds.
5. Look at your heat training materials for language and literacy fit, and build in time for questions.
6. Watch the Cal/OSHA AB 2243 page and the Standards Board agenda for the next step.

Provisio EHS helps California employers build heat illness prevention plans, train supervisors, and get ready for rule changes before they land. Safety-Chat gives crews and supervisors a simple way to run pre-shift heat checks and log close observation in the field. If you want a second set of eyes on your heat program this week, call us at 385-316-2837.

Sources

All retrieved Oct 6, 2026, about 8:20 to 8:35 AM MDT (America/Denver).

• Cal/OSHA, "Cal/OSHA reminds employers to protect workers amid high heat across California," Oct 2, 2026: https://www.dir.ca.gov/DIRNews/2026/2026-79.html
• Cal/OSHA, Assembly Bill 2243 Heat Illness Prevention advisory meetings page (Aug 14, 2026 draft for comment; comments due Sep 21, 2026): https://www.dir.ca.gov/dosh/doshreg/heat-illness/
• Cal/OSHA, Discussion draft language for Title 8 §§ 3395 and 3396 (AB 2243), dated 08-14-26: https://www.dir.ca.gov/dosh/doshreg/heat-illness/Draft-sections-3395-3396-ab2243.docx
• Title 8 § 3395, Heat Illness Prevention in Outdoor Places of Employment (current text): https://www.dir.ca.gov/title8/3395.html
• Occupational Safety and Health Standards Board, 2026 meeting schedule and Oct 15, 2026 agenda: https://www.dir.ca.gov/oshsb/mtgsch.html and https://www.dir.ca.gov/oshsb/documents/agendaOct2026.pdf