On July 24, 2024, California’s Department of Industrial Relations (DIR) announced that the Indoor Heat Illness Prevention regulation, which the Cal/OSHA Standards Board unanimously approved on June 20, 2024, would take effect immediately as a result of a finding of good cause by the Office of Administrative Law (OAL) on July 23, 2024.

The new requirements apply to all indoor work areas where the temperature equals or exceeds 82° Fahrenheit¹ when employees are present, with very few exceptions.² Additional requirements apply if the temperature or heat index equals or exceeds 87° or where employees are wearing clothing that restricts heat removal or work in a “high radiant heat area” and the temperature equals or exceeds 82°.

The following requirements apply to all covered indoor work areas:

Establishing, implementing and maintaining a written Indoor Heat Illness Prevention Plan. The plan can be included in the employer’s existing Injury and Illness Prevention Plan (IIPP), existing Outdoor Heat Illness Prevention Plan (OHIPP), or as standalone Indoor Heat Illness Prevention Plan (IHIPP). At a minimum, the IHIPP must include the following:  

• Procedures for the provision of water.
• Procedures for access to cool-down areas and cool-down rest breaks.
• Procedures to measure the temperature and heat index, identify and evaluate environmental risk factors for heat illness, and implement engineering, administrative and personal heat-protective equipment controls.
• Emergency response procedures.
• Acclimatization and employee observation and monitoring.

Providing water access and encouraging frequent consumption. Employers must provide access to free, potable, suitably cool water as close as practicable to the work area as possible, as well as in indoor cool-down areas. If the water provided is not plumbed, employers must follow certain requirements regarding quantity provided.

Providing access to cool-down areas. Employers must provide a minimum of one cool-down rest area for employees to have duty-free cool-down recovery breaks. Failure to provide cool-down recovery breaks is a violation of the labor code, and employers are required to pay the employee one additional hour of pay at the employee’s regular rate of compensation for each day a recovery period is not provided.

Cool-down areas must be less than 82° unless infeasible, located as close as practicable to work areas, and must be large enough to accommodate a number of employees on recovery, rest breaks, or meal breaks so they can sit in normal positions without physical contact. Employers must also allow and encourage cool-down breaks and follow other specific requirements that apply when employees use cool-down areas including, but not limited to, monitoring the employee for severe illness and improvement of symptoms, providing first aid, and calling emergency medical services.

Assessment of control measures. Additional “assessment and control” measures apply to all indoor workplaces in which any of the following applies: 

• The temperature or heat index equals or exceeds 87° Fahrenheit when employees are present;
• Employees wear clothing that restricts heat removal and the temperature equals or exceeds 82° Fahrenheit; or
• Employees work in a high-radiant heat area and the temperature equals or exceeds 82° Fahrenheit.

When one of the above conditions is present, the below additional requirements are triggered:

• Conducting a more thorough heat hazard assessment.
• Heightened temperature and heat index measuring and recording requirements.
• Deployment of additional engineering controls to reduce both the temperature and heat index to below 87° when employees are present, unless infeasible.
• Where engineering controls are not feasible to achieve the above targets, applying additional administrative controls to reduce both the temperature and heat index to below 87° when employees are present, unless infeasible.
• When additional engineering or administrative controls are not feasible to achieve a temperature and heat index below 87°, deployment of personal heat-protective equipment, unless infeasible.

Emergency response. Employers must ensure an effective communication system is in place so workers can alert a supervisor or emergency medical services if needed. Employers must also develop emergency procedures to respond to employees exhibiting signs of heat illness.

Acclimatization. If the employer is unable to implement engineering controls to control the effect of outdoor heat on the indoor temperature, all employees must be “closely observed” during a “heat wave.” The employer must develop procedures to monitor new employees.

Training. Training on the following topics must be provided to all employees (supervisory and non-supervisory) before the employee with a “reasonable expectation of exposure” begins work:

• The environmental and personal risk factors for heat illness, as well as the added burden of heat load on the body caused by exertion, clothing, and personal protective equipment.
• The employer’s procedures for complying with the requirements of the regulation, including, but not limited to, the employer’s responsibility to provide water, cool-down areas, cool-down rests, control measures, and access to first aid as well as the employees’ right to exercise their rights under this section without retaliation.
• The importance of frequent consumption of small quantities of water, up to four cups per hour, when the work environment is hot and employees are likely to be sweating more than usual in the performance of their duties.
• The concept, importance, and methods of acclimatization and of close observation during acclimatization.
• The different types of heat illness, the common signs and symptoms of heat illness, and appropriate first aid and/or emergency responses to the different types of heat illness, and in addition, that heat illness may progress quickly from mild symptoms and signs to serious and life-threatening.
• The importance of employees’ immediately reporting to the employer, directly or through the employee’s supervisor, symptoms or signs of heat illness in themselves, or in co-workers.
• Procedures for responding to signs or symptoms of possible heat illness, including how emergency medical services will be provided should they become necessary. 

Supervisory employees must receive training on the additional topics set forth below:

• Procedures supervisors must follow to implement the IHIPP.
• Procedures supervisors must follow when an employee exhibits signs or reports symptoms consistent with possible heat illness, including emergency response procedures.
• How to monitor weather reports and how to respond to hot weather advisories, where applicable.

Similar to other Cal/OSHA regulations, this regulation also requires active involvement of employees and unions in the planning, conducting, and recording of the measurements of the temperature or heat index and identifying and evaluating environmental risk factors for heat.

California employers should evaluate their temperature controls and where possible, reduce the temperature of the workplace below 82°. California employers with any work settings that are covered by the new regulation should immediately develop indoor heat illness plans and provide training to their employees to ensure they are compliant. Employers should also be aware that Cal/OSHA may begin enforcing the regulation right away.