Outdoor Heat Illness Prevention Standard

The outdoor heat illness standard applies only to “outdoor places of employment.”1

Sometimes what’s considered an outdoor place of employment is obvious. For example, outdoor places of employment clearly include open spaces:

• Agricultural fields;
• Road work;
• Landscaping; and
• Construction sites.

Other obvious examples, according to Cal/OSHA, include forests, parks, equipment and storage yards, outdoor utility installations and tarmacs.

Cal/OSHA also considers construction sites with no completed building shell and construction areas outside of any building shells as outdoor places of employment. Outdoor areas adjacent to buildings - loading docks, for example - may also be considered outdoor places of employment.

Indoor Heat Illness Prevention Standard

• Cal/OSHA’s indoor heat illness prevention standard, effective July 23, 2024, applies to “all indoor work areas where the temperature equals or exceeds 82°F when employees are present.”2 There are, however, some exceptions. The indoor standard doesn’t apply to the following:

• Places of employment where workers are teleworking from a location of the employees’ choice, which is not under the employer’s control.
• Emergency operations that are directly involved in the protection of life or property.
• Incidental heat exposures where a worker is exposed to temperatures at or above 82°F and below 95°F for less than 15 minutes in any 60-minute period. This exception does not apply to:
• Vehicles without effective and functioning air conditioning.
• Shipping or intermodal containers during loading, unloading or related work.
• Prisons, local detention facilities and juvenile facilities.

Cal/OSHA guidance clarifies that indoor places of employment are spaces that are under a ceiling or overhead covering that restricts airflow and enclosed along the entire perimeter by walls, doors, windows, dividers, or other physical barriers that restrict airflow, whether open or closed. Generally, any workplace with a roof and enclosed sides is considered an indoor workplace.

Work areas that aren’t indoors are considered outdoors and covered by the outdoor heat illness prevention standard. Additionally, “indoor place of employment” does not refer to a shaded area used exclusively as a source of shade and cooling for workers working in hot outdoor environments. Partial structures such as lean-tos and structures with one or more open sides are outdoor workplaces, subject to the outdoor heat illness prevention standard.

• Consult legal counsel if you have any questions about whether you are covered by either the outdoor or indoor heat illness prevention standards.

Cal/OSHA also has educational materials with recommendations for preventing heat illness. For more information, visit the Cal/OSHA website.

Providing WaterUnder both the outdoor and indoor heat illness standards, you must provide employees with free, ready access to fresh, pure, suitably cool, potable drinking water. The water must meet the requirements set forth in the California Code of Regulations, Title 8 section 1524 (Water Supply), section 3363 (Water Supply) and section 3457 (Field Sanitation), as applicable.3

The water must be located as close as practicable to where employees are working and, for indoor areas, close to indoor cool-down areas required by the indoor heat illness standard. To ensure that water is fresh, pure, and suitably cool, Cal/OSHA advises employers or supervisors to visually examine, smell/taste the water, and pour some on their skin.

Providing sufficient water may require placing water strategically in multiple locations, such as when workers are working in large areas. For example, in a large warehouse, water should be placed in safely accessible locations throughout the building in all areas where workers are working. In the outdoor context, on a multi-level construction site, for example, water would be placed on every floor in a safe, accessible location. According to Cal/OSHA guidance, placing water only in designated shade areas or where toilet facilities are located is not sufficient.

Cal/OSHA’s guidance states that the water must be fit to drink and free from odors that would discourage workers from drinking it. Containers provided to employees must be clean and a source of potable water (e.g. a municipal water source) must be readily available. Water provided from non-approved, non-tested water sources (e.g. untested wells) is, according to the guidance, unacceptable. During hot weather, Cal/OSHA states that water must be “cooler than the ambient temperature.”

The water must be located as close as practicable to where employees are working. Pursuant to the guidance, Cal/OSHA states that during any inspection, the inspector may ask the supervisor to describe factors the employer considered when deciding where to place the water. Cal/OSHA also states that when employees are working across large areas, water should be placed in multiple locations. For instance, on a multi-level construction site, water would be placed on every floor in a safe, accessible location. According to the guidance, placing water only in designated shade areas or where toilet facilities are located is not sufficient.

Cal/OSHA outdoor heat illness standard guidance states that during any inspection, the inspector may ask the supervisor to describe factors the employer considered when deciding where to place the water.

Containers provided to employees must be clean, and a source of potable water (e.g. a municipal water source) must be readily available. Water provided from non-approved, non-tested water sources (e.g. untested wells) is, according to the guidance, unacceptable.

If the work area does not contain plumbing to continuously provide suitable drinking water, you must provide a sufficient quantity of water. At the beginning of the work shift, you must provide enough for each employee to drink one quart for each hour of the shift. You can begin the shift with smaller quantities of water if you have an effective procedure for replenishing the water during the shift. Employees must be allowed to drink one quart of water or more per hour. You must encourage employees to drink water frequently.

1. 8 CCR sec. 3395(a)

2. 8 CCR sec. 3395(a)

3. 8 CCR sec. 3395(c),3396(c)