In July 2024, Cal/OSHA officially adopted a long-awaited regulation focused on preventing heat illness in indoor workplaces. Before this, California’s heat-illness rules applied almost entirely to outdoor work. With hotter summers and an increase in indoor environments reaching dangerous temperatures, the state expanded protections to cover indoor workers as well.
Under this new regulation, any indoor workplace that reaches 82°F now triggers specific employer obligations. These include providing easily accessible drinking water, offering a designated cool-down area kept below 82°F, and training employees on the signs, symptoms, and prevention of heat illness.
When indoor temperatures rise above 87°F — or above 82°F where workers wear heavy protective clothing or are exposed to radiant heat — stricter requirements apply. Employers must implement engineering controls (such as improved ventilation or cooling systems), adjust work-rest schedules, and offer protective equipment to reduce heat exposure.
Industries like manufacturing, warehousing, commercial kitchens, and even office environments with poor cooling may all be affected. Cal/OSHA has emphasized that extreme heat is becoming more common indoors, and employers can no longer assume heat illness is only an outdoor risk.
Why this matters: This regulation marks a major shift in California workplace safety. Employers need to evaluate their indoor environments, update their heat-illness prevention plans, and proactively prepare for high-temperature days. Workers gain stronger rights to rest, hydration, and safe conditions when indoor heat becomes hazardous.