New Draft Cal/OSHA Indoor Heat Illness Standard Significantly Alters Scope

By Megan Shaked and Rachel Conn

On November 9th, right before the Veterans Day holiday, the California Occupational Safety & Health Standards Board issued its 15-day Notice for the latest draft of the Indoor Heat Illness Standard. The revisions come following a comment period on the draft released August 4, 2023, and include significant changes to the regulation’s scope and application.


New Exception for Incidental Heat Exposure: The draft adds an exception for “incidental heat exposures where an employee is exposed to temperatures above 82 degrees Fahrenheit for less than 15 minutes in any 60 minute period”.

However, this exception does not apply under any of the following conditions:

  • the temperature equals or exceeds 87˚F when employees are present;
  • the heat index equals or exceeds 87˚F when employees are present;
  • employees wear clothing that restricts heat removal and the temperature equals or exceeds 82˚F; or
  • employees work in a high radiant heat area and the temperature equals or exceeds 82˚F

New Exception for Emergency Operations: Under the current draft, the indoor heat regulation does not apply to “emergency operations directly involved in the protection of life or property.” “Emergency operations,” however, is not defined in the proposed regulation.

Exceptions Removed:

The new exception for incidental heat exposure appears to be taking the place of an exception that has now been removed. Under the previous draft, there was an exception that allowed certain indoor locations to be considered outdoor locations subject to 8 CCR 3395 (Heat Illness Prevention in Outdoor Places of Employment) rather than the indoor heat regulation. In order to qualify for that exception, the following criteria needed to be met: the indoor location is not normally occupied when employees are present or working in the area or at the worksite; the indoor location is not contiguous with a normally occupied location; and employees are present in the indoor location for less than 15 minutes in any one-hour period. The previous draft explicitly stated that this exception did not apply to “vehicles or shipping containers.”

The current draft also removes an exception that allowed employers to comply with the indoor heat illness regulation in lieu of compliance with the outdoor heat illness regulation for employees who go back and forth.

As such, under the current draft, Cal/OSHA has removed employers’ ability to streamline some of the compliance obligations when an employer may be subject to both the indoor and outdoor heat illness regulations.  Employers are still permitted to integrate their training programs where employees are covered by both the indoor and outdoor heat regulations.


Definition Added:

The revised draft adds a definition for “high radiant heat source,” which means “any object, surface, or other source of radiant heat that, if not shielded, would raise the global temperature of the cool-down area five degrees Fahrenheit or greater than the dry bulb temperature of the cool down area.” The term “high radiant heat source” is used within the definition of cool-down area.

Appendix A:

Finally, Cal/OSHA made some adjustments to the temperatures referenced in the National Weather Service Heat Index Chart, which is included as Appendix A to the regulation.

What comes next?

The latest revised draft is subject to a 15-day comment period. All comments are due by November 28, 2023 (the Tuesday after the Thanksgiving holiday). The next Standards Board meeting will be held this Thursday, November 16, 2023. The December Standards Board meeting is scheduled for December 14, 2023. At these meetings, we expect significant discussion from stakeholders, Cal/OSHA, and the Standards Board regarding these latest changes. Conn Maciel Carey’s Cal/OSHA Team will provide additional updates on this blog regarding developments. If the Standards Board intends to vote on adopting this standard in the first quarter of 2024, this may be the final draft.

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