645 Heat Injury and Illness Prevention: Employee

California Requirements

Application & Scope

This section supplements OSHAcademy Course 645: Heat Injury and Illness Prevention (Employee) and is designed to align the training with the California Division of Occupational Safety and Health (Cal/OSHA) heat illness prevention standards. For more in-depth review or questions about exceptions to the standards please click on the applicable link below:

• Title 8 Section 3395 – Heat Illness Prevention (Outdoor Workplaces)
• Title 8 Section 3396 – Heat Illness Prevention (Indoor Workplaces)
• Title 8 Section 3203 - Injury and Illness Program

These standards establish legally enforceable requirements for protecting employees who work in outdoor environments and indoor areas where environmental or operational heat may create a risk of heat stress or heat illness.

Environmental Triggers

Shade / Cool-Down Areas

Employers must:

• Provide shade that is within 0.25 miles on foot as close as practicable to the worksite
• Shade must be open and ventilated on at least three sides, free of added heat sources (e.g., running vehicles) and must be of adequate size so workers may sit without crowding
• Shade must not be so unsafe, unhealthy or unsanitary that workers are discouraged from using it
• For outdoor range, ranch or remote mobile worksites, employers must allow and permit employees to seek and use shade during rest/meal periods
• Indoor cool-down areas must meet §3396 requirements: kept below 82°F, protected from radiant heat/direct sun, large enough for employees, located as close as practicable to the working area

Drinking Water

Employers must:

• Provide fresh, pure, and suitably cool potable water free of charge
• Supply at least 1 quart (≈ 32 oz) per employee per hour
• Water must be located as close as practicable to where employees are working, and time must be allowed for employees to drink water and use restrooms as needed
• For mobile/range workers distant from a fixed water supply, the employer must still comply to the maximum extent feasible, including re-supplying water or providing equipment for employees to safely carry or obtain potable water.

Acclimatization

• Outdoor work: Supervisors or their designees must closely observe all employees during a heat wave. For the purposes of this section, "heat wave" means any day when the forecasted high temperature is at least 80°F and at least 10°F higher than the average daily high over the preceding five days. An employee who has been newly assigned to a high heat area shall be closely observed by a supervisor or designee for the first 14 days of the employee's employment.
• Indoor Work: Where no effective engineering controls are in use to control the effect of outdoor heat on indoor temperature, all employees shall be closely observed by a supervisor or designee during a heat wave. An employee who is newly assigned to any of the following duties or work environments must be closely observed by a supervisor or designee for the first 14 days of the employee's employment.
  • In a work area where the temperature or heat index, whichever is greater, equals or exceeds 87 degrees Fahrenheit
  • In a work area where the temperature equals or exceeds 82 degrees Fahrenheit for employees who wear clothing that restricts heat removal
  • In a high radiant heat area where the temperature equals or exceeds 82 degrees Fahrenheit

Heat Wave & Weather Monitoring

Supervisors must monitor daily NWS forecasts. When a heat wave (unusually high temps) is predicted:

• Review high-heat procedures.
• Increase observations and rest opportunities.
• Provide extra reminders to hydrate.

Written Plan & Accessibility

• Maintain a written Heat Illness Prevention Plan (HIPP) at the worksite.
• Plan must be readily available to employees, representatives, and Cal/OSHA inspectors.
• Provide training and plan in both English and the language understood by the majority of the employees.

Training Requirements

All employees must receive training before first exposure to job assignments covered by §3395 or §3396 when thresholds (≥80°F outdoor, ≥82/87 °F indoor) are reasonably expected. Refresher training must be conducted annually, and immediately after any heat-related illness incident and training must be provided in a language and manner that employees understand.

Ensure employees receive instruction on:

• Environmental & personal risk factors for heat illness
• Procedures for providing water, shade, cool-down rests
• The importance of frequent consumption of small quantities of water
• Acclimatization methods for new/returning workers
• Different types of heat illness
• Emergency response and EMS contact procedures
• Worker rights to water, shade, and rest without penalty
• The employer's specific HIPP

Ensure supervisors receive additional training on:

• The procedures to follow to implement the Heat Injury and Illness Plan
• The procedures to follow when an employee exhibits signs or reports symptoms of heat illness, including emergency response procedures.
• How to monitor weather reports and how to respond to hot weather advisories.

Recordkeeping & Verification

• Maintain training records ≥ 1 year (Title 8 §3203). Records should include:
  • names of attendees
  • date of training session
  • summary of training content
• Document high-heat meetings, weather monitoring, and incident responses.
• Keep records accessible for Cal/OSHA inspection.

Best-Practice Enhancements (from ANSI A10.50)

• Optional WBGT or adjusted heat index measurements for earlier preventive actions.
• Periodic program reviews and corrective actions.

Note: Employers must supplement OSHAcademy Course 645, Heat Injury and Illness Prevention: Employee, with site-specific training or a HIPP orientation that explains the equipment and procedures used at the worksite to prevent heat injury and illness.

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