California Indoor Heat Rule
Warehouses, kitchens, factories, laundries and buildings under construction can get dangerously hot. Since July 2024, California’s indoor heat illness standard, Title 8 §3396, requires employers to protect workers in hot indoor workplaces, alongside the long-standing outdoor rule.
- General Industry
- Construction
- Warehouses
- California
Photo: warehouse worker checking a wall-mounted thermometer and heat index display near a cooling fan
When it applies
- Indoor work areas where the temperature reaches 82°F while employees are present.
- “Indoor” means a space under a ceiling or overhead covering that restricts airflow and is enclosed along its entire perimeter by walls, doors or windows, whether or not they’re open.
- If you work both indoors and outdoors, the outdoor rule (§3395) covers the outdoor work.
Basic protections (82°F and up)
- Fresh, suitably cool drinking water, free, close to the work, enough for about a quart per worker per hour
- Cool-down areas kept below 82°F where possible, big enough for workers on break
- Preventive cool-down rest whenever a worker asks for it, with close watching for symptoms
- Acclimatization: close observation of new workers and workers during a heat wave for their first 14 days
- Emergency response procedures
- Training for workers and supervisors
- A written Heat Illness Prevention Plan (it can be part of the company IIPP)
More protections at higher heat
Employers must also measure the temperature and heat index, record the results, and use controls when:
- The temperature or heat index reaches 87°F, or
- Workers wear clothing that restricts heat removal, or work in high radiant heat, and the temperature reaches 82°F.
| Type of control | Examples |
|---|---|
| Engineering controls (first choice) | Air conditioning, cooling fans, evaporative coolers, ventilation, insulating or shielding hot equipment |
| Administrative controls | Moving hot work to cooler times of day, rotating workers, slowing the pace of work, more rest breaks |
| Personal heat protective equipment | Cooling vests and other cooling gear, when other controls aren’t enough |
Exemptions
- Short exposures: less than 15 minutes in any 60-minute period at 82°F or more
- Emergency operations, like disaster response
- Workers teleworking from a place they choose
- Some workplaces already covered by other Cal/OSHA heat rules
Exemptions have conditions. Check the standard or Cal/OSHA for details.
Workers: You can ask for a cool-down break at any time when you feel you need one, and you can’t be punished for it. If your workplace is hot and there’s no water, cool-down area or plan, you can file a complaint with Cal/OSHA. See California (Cal/OSHA).
Standards & references
- Title 8 §3396: Heat illness prevention in indoor places of employment
- Cal/OSHA: Heat illness prevention
- See also: Heat Illness Rules by State · Heat Illness Prevention · Warehouse Safety
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