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An Employer's Guide to California's Heat Illness Prevention Regulations

  • May 23, 2014

As the days grow warmer, California employers with outdoor places of employment should think about compliance with California’s Heat Illness Prevention Regulations (Cal. Code of Regs. tit. 8, § 3395). To comply with the regulations, California employers should take four essential steps:

  • Develop and implement written procedures for addressing heat illness prevention; 
  • Train employees and supervisors; 
  • Provide adequate water; and
  • Provide adequate shade.


The regulations apply to all employers with outdoor places of employment, although certain industries must follow additional “high heat” procedures when the temperature reaches or exceeds 95 degrees Fahrenheit. In its Heat Illness Enforcement Q&A (, the Division of Occupational Safety and Health of the California Department of Industrial Relations states that regulations apply at all times when employees are at work outdoors.

The Division interprets “outdoor places of employment” to include any open area, including fields, forests, parks, yards, roads, construction sites, and outdoor areas adjacent to buildings, such as loading docks. Sheds and temporary structures may be considered outdoor places of employment depending on whether the structure decreases the risk of heat illness. If the structure does not significantly reduce the net effect of the environmental risk factors for heat illness, the Division would consider it an “outdoor place of employment.” The Division has taken the position that employees who spend any significant amount of time working outside would create an outdoor place of employment.

Written Procedures and Training

Employers must develop and implement written procedures for complying with the requirements of this standard. The procedures should address the following:

  • Access to water and shade;
  • Water replenishment;
  • Acclimatization and weather monitoring;
  • For certain industries, additional “high heat” procedures to take effect when temperatures reach or exceed 95 degrees Fahrenheit;
  • Employee and supervisor training;
  • Responding to symptoms of possible heat illness; and 
  • Providing emergency medical services. 

These written procedures must be made available to employees and to the Division upon request. Employers may integrate these requirements into their existing Injury and Illness Prevention Programs. 

The regulations require employers to provide training regarding heat illness to employees and supervisors. To be effective, the training should be in a format and language that is understandable to the employees. It must cover environmental and personal risk factors for heat illness, the employer’s heat illness prevention procedures (including procedures for reporting signs or symptoms of heat illness and for responding to possible heat illness, including emergency procedures), the importance of frequently drinking water in small quantities, the importance of acclimatization, the different types of heat illness, and the common signs and symptoms of heat illness, among other things. 

In addition to the above topics, training for supervisors must address the following topics:

  • Procedures to implement the regulations (e.g., provision of water and shade, weather monitoring, and acclimatization issues);
  • Procedures to follow when an employee exhibits symptoms consistent with possible heat illness, including emergency response procedures and first aid; and
  • How to monitor weather reports and respond to hot weather advisories.

Additional information regarding heat illness prevention is available at the Cal-OSHA Heat Illness webpage, 

Provision of Water

The regulations require employers to provide potable, cool drinking water at all times at no cost to the employee in locations readily accessible to employees. In very hot weather, the Division recommends that employers have ice on hand to keep the water cool. All water containers must be filled directly from a potable water supply and cannot be refilled from non-potable water sources (e.g., sprinkler systems) or from non-approved or non-tested water sources (e.g., untested wells).

Where unlimited drinking water is not immediately available through plumbing or other source, employers must provide enough water for every employee to be able to drink one quart of water, or four 8-ounce cups, per hour. If employers choose not to provide the full-shift quantity of drinking water at the start of a work shift, effective procedures for drinking-water replenishment must be developed. A sufficient quantity of water must always be present to allow every employee to consume at least one quart of water per hour until the water supply has been replenished. 

Employers also must locate water containers as close as practicable to the workers, given the working conditions and worksite. If workers move from one area to another, employers should move the water with the workers. Employers also should encourage the frequent drinking of small quantities of water throughout the day, especially during periods of high heat. 

Access to Shade

When the temperature exceeds 85 degrees Fahrenheit, employers must maintain one or more areas with shade at all times while employees are present. Employees must be allowed to remain in the shade for at least five minutes whenever they feel the need to do so to avoid overheating, and employers should encourage employees to do so. 

The shaded area either must be open to the air or provided with ventilation or cooling. The shaded area must be large enough to accommodate 25 percent of the employees on a shift at one time and allow them to sit comfortably and fully in the shade in a normal posture without having physical contact with each other. The shaded area must be as close as practicable to the area where employees are working.

When the temperature does not exceed 85 degrees Fahrenheit, employers must provide prompt access to shade when requested by an employee. 

If it is unsafe or infeasible to provide shade, the employer may provide equivalent protection, document its determination, and specify what alternatives will be provided. Non-agricultural employers may provide cooling measures other than shade, such as misters, if they can demonstrate that the alternative is at least as effective as shade.

High Heat Protocols

In addition to the above requirements, employers engaged in  agriculture, construction, landscaping, oil and gas extraction, and in certain types of transportation, or delivery companies involved in agricultural products, construction materials or other heavy materials must develop additional protocols to address heat at or above 95 degrees Fahrenheit. These protocols include:

  • Ensuring that effective communication by voice, observation, or reliable electronic means (e.g., cell phone) is maintained so that employees at the work site can contact a supervisor when necessary;
  • Observing employees for alertness and signs or symptoms of heat illness;
  • Reminding employees throughout the work shift to drink plenty of water; and
  • Closely supervising any new employee for the first 14 days of employment, unless the new employee indicates at the time of hire that he or she has been doing similar outdoor work for at least 10 of the past 30 days for 4 or more hours per day. 

Monitoring and Acclimatization

Employers are responsible for the working conditions of their employees, and thus the Division expects employers to monitor the weather, particularly for approaching heat waves. Supervisors should use a thermometer to keep track of the temperature at the worksite on hot days. A simple, dry bulb thermometer can be used to measure the outdoor temperature. 

In addition to monitoring weather reports, employers must be aware of the risks of heat illness due to inadequate acclimatization. Acclimatization is the body’s gradual adaptation to working in the heat. In general, acclimatization peaks in most people within four to 14 days of regular work for at least two hours per day in the heat. New employees are most at risk for heat illness due to inadequate acclimatization. 

Penalties for Non-Compliance

Employers that fail to comply with the regulations risk significant penalties, including serious classifications, if there is a realistic possibility of a death or serious injury. In addition, employers who fail to provide recovery or “cool-down” breaks in accordance with these regulations could be liable for one hour of pay for each missed recovery period. (For additional information regarding recovery periods, see The Heat is on for Calif. Employers.) 


California employers should consult with experienced counsel to develop an appropriate response and strategy should they receive a citation or is investigated for violations of the Heat Illness Prevention Regulations.

©2014 Jackson Lewis P.C. This material is provided for informational purposes only. It is not intended to constitute legal advice nor does it create a client-lawyer relationship between Jackson Lewis and any recipient. Recipients should consult with counsel before taking any actions based on the information contained within this material. This material may be considered attorney advertising in some jurisdictions. Prior results do not guarantee a similar outcome.

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