On August 14, 2026, the California Division of Occupational Safety and Health (Cal/OSHA) published further revisions to the draft changes to title 8 of the California Code of Regulations (CCR), sections 3395 (Heat Illness Prevention in Outdoor Places of Employment) and 3396 (Heat Illness Prevention in Indoor Places of Employment). Cal/OSHA has been in the process of revising these two standards to comply with Assembly Bill (AB) 2243, enacted in September 2022.
While many of the proposed changes are relatively minor fixes that improve the consistency of wording or organization between the two regulations, there are several substantive changes that employers should take note of.
Key Proposed Changes
- Expansion of employers covered by high heat: All employers who have employees working outdoors and exposed to the hazard of heat illness will need to comply with the high heat procedures in subsection 3395(e). Currently, 3395 excludes employers (those outside of agriculture, construction, landscaping, oil and gas production, and some transportation) from complying with 3395(e)’s high heat procedures.
- Acclimatization updates: Proposed changes to the “Acclimatization” section of 3396 will make it easier for employers to determine if a newly assigned or newly returned employee needs “close observation” by simplifying the threshold for making that determination to either a temperature of 82 degrees Fahrenheit or a heat index of 87 degrees Fahrenheit, without needing to evaluate whether an employee wears clothing that restricts heat removal or works in a high radiant heat area.
- Updates to the “Acclimatization” sections for both regulations give employers a choice between conducting pre-shift meetings on heat topics or limiting exposure to heat for employees who need to be acclimatized. It also requires limiting exposure for public safety personnel engaged in high-intensity physical training while they are acclimatizing.
- Training must account for literacy levels: Proposed changes to the training subsections for both regulations would require employers to take the literacy level of employees into account when giving training, and make sure there is an opportunity for employees to ask questions during training.
- Cal/OSHA may require wearables: Proposed subsection (j), new to both regulations, reiterates that Cal/OSHA may issue Orders to Take Special Action to employers. It specifically suggests that one of these orders may be for employers to monitor employees’ response to heat stress with the use of wearable devices that track the employees’ biometric data, but that the employer would have to ensure that health data is secure and not used to discriminate against employees.
Cal/OSHA’s ability to issue Orders to Take Special Action is not new and is already codified at t8 CCR section 332.3. The suggestion that Cal/OSHA would order employers to collect biometric health data from their employees is novel and potentially problematic for both employers and employees, especially when it comes to privacy and other employment-related laws.
Summary of All Proposed Changes
In addition to the key changes outlined above, below is a summary of the additional proposed changes.
Scope and Application (3395(a) and 3396(a))
For Section 3395(a), the proposed changes remove the exception that employers outside of agriculture, construction, landscaping, oil and gas production, and transportation or delivery of agricultural products, construction materials, or other heavy materials do not need to comply with the High Heat procedures found in 3395(e).
No changes beyond punction correction are made to Section 3396.
Definitions (3395(b) and 3396(b))
The changes in the “definitions” section are identical for both sections.
- The draft adds in “closely observed” as a defined term, meaning to “effectively monitor an employee to detect early signs of heat illness and trigger a prompt response when needed.”
- Effectively monitoring an employee includes frequent visual observation and frequent two-way verbal communication with on-site workers, and frequent two-way communication with remote workers, sufficient to detect if someone is exhibiting behavior signs of heat illness like “fatigue, shortness of breath, irritability, confusion, disorientation, odd behavior and changes in personality.”
- Rhabdomyolysis is added to the medical conditions that are defined as “heat illness.”
- Rhabdomyolysis is a condition where damaged muscle tissue breaks down quickly, releasing proteins and electrolytes into the bloodstream. It can be asymptomatic but can also cause muscle cramps and pain, abnormally dark urine, muscle weakness, exercise intolerance, or death.
- The definition of “Heat Wave” is unchanged but moved from subsection 3395(g)(1) to the “Definitions” subsection 3395(b) to bring it into alignment with Section 3396(b).
- Use of “supplements” and use of “recreational drugs” are added to the personal risk factors for heat illness (factors that affect a person’s water retention and bodily response to heat).
- “Signs and symptoms of heat illness” is defined as “physiological or behavioral manifestations of heat illness” including but not limited to heat cramps, heat exhaustion, rhabdomyolysis, heat syncope, and heat stroke. Each of these conditions is briefly described in the definition.
Access to Shade (3395(d)) and Cool-Down Areas (3396(d)
New language added to section 3395(d)(4) clarifies that “preventative cool-down rest period” has the same meaning as “recovery period” in Labor Code subsection 226.7(a) (“a cooldown period afforded an employee to prevent heat illness”).
This reference to the Labor Code was previously at 3395(e)(6). Moving it to subsection (d) brings 3395 into closer alignment with section 3396(d) (Access to Cool-Down Areas), which remains unchanged.
High-heat Procedures (3395(e) and 3396(d))
Minor re-wording to 3395(e)(6) clarifies that when temperatures reach 95 degrees or above, employers shall ensure that every two hours during a shift, employees take a minimum ten-minute cool-down break, and that time to get to the shade is not included in that break time.
Section 3396 is unchanged.
Acclimatization (3395(g) and 3396(g))
For section 3395, the definition of “heat wave” is unchanged but moved to the “Definitions” subsection 3395(b).
A change to subsection 3395(g)(2) reduces ambiguity in the term “high heat area” by re-wording to say that close observation shall be conducted, “when a newly assigned employee or an employee returning to work after an absence of more than 14 days is assigned to a location where the predicted high temperature for the day will be at least 80 degrees Fahrenheit….”
Changes to 3396(g)(2) simplify the requirements for when a newly assigned or returning employee needs close observation in indoor workspaces where the temperature equals or exceeds 82 degrees Fahrenheit or the heat index equals or exceeds 87 degrees Fahrenheit. The prior requirements to compare the temperature and the heat index to determine which is greater, and lower temperature threshold for employees wearing clothes that restrict heat removal or work in high radiant heat areas are removed.
For both 3395 and 3396, a new section added to subsection (g) gives employers a choice between conducting pre-shift meetings on heat topics or limiting employee exposure to heat for workers who need to be acclimatized. For the meeting option, on days when close observation of employees is required to remind employees of signs of heat illness, emergency response procedures, and their right to take cool-down rests, among other things. In the alternative, employers may restrict the employee’s exposure to heat to a percentage of the employee’s shift that progressively increases over the first three or four days of work.
Public safety personnel (law enforcement, firefighting, and emergency response personnel) who are newly assigned or returning to work shall have their exposure to heat initially restricted and gradually increased over three or four days if they are engaged in high-intensity physical training.
The changes to subsection (g) also include an exception for employers who can show that an employee consistently worked under similar conditions for the prior 14 days.
Training (3395(h) and 3396(h))
The proposed change for training is that employers must provide it in a language and at a literacy level each employee understands, and employers must give employees a chance to ask questions about the training materials. This change is identical in both 3395 and 3396.
Heat Illness Prevention Plan (3395(i) and 3396(i))
The proposed change (identical in both sections) requires an employer to distribute a written copy of its Heat Illness Prevention Plan to new employees when they are hired, during heat illness prevention training, and at least once a year thereafter, though employers need to distribute it to employees more than twice a year.
It also gives employers the option to post the Heat Illness Prevention Plan online in English, and in a format that can be easily translated to other languages, in lieu of giving physical copies to employees.
Orders (3395(j) and 3396(j))
New subsection (j) is proposed in this draft. This subsection, identical in both 3395 and 3396, states that Cal/OSHA may issue an Order to Take Special Action to an employer. Authority for Cal/OSHA to do so already is codified at title 8, section 332.3. The new subsection specifically says that the special action may include, but is not limited to, “the use of wearable technology that monitors the user’s physiological responses to heat stress, where the employer is responsible for ensuring that health data is kept secure and not used to discriminate against employees.”
What’s Next
Cal/OSHA invites public comment on the most recent revisions by September 21, 2026. Comments can be submitted to Cal/OSHA’s Research and Standards Unit by email at rs@dir.ca.gov.
For more information on Cal/OSHA’s proposed revisions or on the current heat illness prevention regulations, please contact Rachel L. Conn and Kathryn Tanner.
