LOS ANGELES, California: On the first day of summer, as parts of California sweltered under a heat advisory, the state's worker safety board approved new standards to protect indoor workers from excessive heat.

However, these protections will exclude state correctional facilities.

The California Division of Occupational Safety and Health (Cal/OSHA) board initially passed indoor heat rules in March, but Democratic Governor Gavin Newsom's administration blocked them due to concerns about costs for prisons and other state entities.

The revised rules, set to impact about 1.4 million workers and 196,000 establishments, now await final approval from the Office of Administrative Law. Cal/OSHA board chair Joseph M. Alioto Jr. has requested expedited approval.

These heat rules aim to prevent heat stress-related illnesses, injuries, permanent disabilities, and deaths among workers such as greenhouse and warehouse employees, kitchen staff, teachers, custodians, and bartenders. California joins several other states, including Oregon and Minnesota, to establish indoor worker protections.

The regulations come amid rising global temperatures and the absence of federal heat standards for U.S. workers. This week's record-breaking heat across the Midwest and Northeast has highlighted the need for such measures, with 418 work-related heat exposure deaths reported between 2012 and 2022, according to the U.S. Bureau of Labor Statistics.

The new rules will apply to workplaces like warehouses, schools, and kitchens. Employers must cool workspaces or adjust tasks or schedules to reduce heat illness risk when temperatures or the heat index reach 87 degrees Fahrenheit (30.5 Celsius), or 82 degrees (about 28 Celsius) where workers wear restrictive attire. At 82 degrees, workers will be entitled to water, breaks, and cooling-off areas, and employers will have to monitor for signs of heat illness. However, employees exposed to temperatures from 82 to 94 degrees Fahrenheit (30.5 to 34.5 Celsius) for less than 15 minutes per hour will be exempt.

California has had outdoor heat protection rules for agriculture and construction since 2006, but indoor heat protections have taken years to develop despite a 2016 state law requiring standards for indoor workers. Reports of heat-stress incidents in indoor workplaces have increased in recent years.

During public comments, labor organizations and state agencies praised the new rules as urgent and overdue. "The standard will help workers stay safe from the increasing threat of high heat on the job, especially as we continue to see record-breaking heat and heat-related deaths on the rise," said Alice Berliner from the Los Angeles County Department of Public Health.

However, some expressed concerns. Robert Moutrie from the California Chamber of Commerce noted that small employers who rent and do not control indoor temperatures may struggle to provide required cool-down areas. Additionally, there was opposition to excluding correctional facilities from the regulations. AnaStacia Nicol Wright from the workers' rights organization Worksafe said that the California Department of Corrections and Rehabilitation employs thousands of staff at risk of heat exhaustion due to working in poorly ventilated buildings.

"These workers are at risk of heat exhaustion and dehydration due to working in often archaic, poorly ventilated buildings with little protection from temperatures, and that will only worsen in the coming years," Wright said.

The state estimates that compliance with the new rules will cost businesses approximately $1 billion over the next decade.