Cal/OSHA Heat Illness Prevention Guidance and Resources

Indoor Heat Requirements

On June 20, 2024, the Occupational Safety and Health Standards Board approved California Code of Regulations, Title 8, section 3396, “Heat Illness Prevention in Indoor Places of Employment”. This standard applies to most workplaces where the indoor temperature reaches 82°F. It establishes required safety measures for indoor workplaces to prevent worker exposure to risk of heat illness. This standard went into effect on July 23, 2024.

For outdoor heat illness prevention, refer to Title 8, section 3395.

In California, employers must take steps to protect workers from heat illness in both indoor and outdoor workplaces under California Code of Regulations, Title 8 (T8CCR), sections 3395 and 3396. Employers may be covered under both the indoor and outdoor regulations if they have both indoor and outdoor workplaces.

Comparison of Indoor and Outdoor Heat Illness Prevention Standards

Requirement Outdoor Heat (T8CCR 3395) Indoor Heat (T8CCR 3396)
Scope and Application
  • Applies to outdoor workplaces
  • Applies to indoor workplaces when the indoor temperature is greater than 82°F
Provide Clean Drinking Water
  • Provide access to potable water that is fresh, suitably cool, and free of charge
  • Located as close as possible to work areas
  • Provide access to potable water that is fresh, suitably cool, and free of charge
  • Located as close as possible to work areas and cool-down areas
Access to Shade and Cool-Down Areas
  • For outdoor workplaces, shade must be present when temperatures are greater than 80°F. When temperatures are less than 80°F, shade must be available upon request
  • For indoor workplaces, provide access to at least one cool-down area which must be kept at a temperature below 82°F
  • Shade and cool-down areas must be:
  • Blocked from direct sunlight
  • Large enough to accommodate the number of workers on rest breaks so they can sit comfortably without touching each other
  • Close as possible to the work areas
  • For indoor workplaces, the cool-down areas must be kept at less than 82°F and shielded from other high-radiant heat sources
Cool-Down Rest Periods
  • Encourage workers to take preventative cool-down rest periods
  • Allow workers who ask for a cool-down rest period to take one
  • Monitor workers taking such rest periods for symptoms of heat-related illness
High-Heat Procedures
  • Have and implement procedures to deal with heat when the temperature equals or exceeds 95°F
  • Procedures must include:
  • Observing and communicating effectively with workers
  • Reminding workers to drink water and take cool-down rest breaks
  • Not applicable to Indoor Workplaces
Assessment and Control Measures
  • Not applicable to Outdoor Workplaces
  • Measure the temperature and heat index and record whichever is greater whenever the temperature or heat index reaches 87°F (or temperature reaches 82°F for workers working in clothing that restricts heat removal or high-radiant-heat areas)
  • Implement control measures to keep workers safe. Feasible engineering controls must be implemented first.
Monitoring the Weather
  • Monitor outdoor temperature and ensure that once the temperature exceeds 80°F, shade structures will be opened and made available to the workers
  • When it is at least 95°F, implement high-heat procedures
  • Train supervisors on how to check weather reports and how to respond to weather advisories
  • For indoor workplaces that are affected by outdoor temperatures, train supervisors on how to check weather reports and how to respond to hot weather advisories

 

Emergency Response Procedures
  • Provide first aid or emergency response to any workers showing heat illness signs or symptoms, including contacting emergency medical services
Acclimatization
  • Closely observe new workers and newly assigned workers working in hot areas during a 14-day acclimatization period, as well as all workers working during a heat wave
Training
  • Employers must provide training to both workers and supervisors
Heat Illness Prevention Plan
  • Establish, implement, and maintain an effective written Outdoor Heat Illness Prevention Plan that includes procedures for providing drinking water, shade, preventative rest periods, close observation during acclimatization, high-heat procedures, training, prompt emergency response
  • Establish, implement, and maintain an effective written Indoor Heat Illness Prevention Plan that includes procedures for providing drinking water, cool-down areas, preventative rest periods, close observation during acclimatization, assessment and measurement of heat, training, prompt emergency response, and feasible control measures

Cal/OSHA recommends the guidance, educational materials, model programs, and other resources that are provided below, be reviewed with an employer's existing procedures to ensure that workers are protected.

Indoor Heat Illness Prevention

Outdoor Heat Illness Prevention

July 2024