The hidden cost of California’s hot workplaces: 20,000 job injuries a year

With more heat waves expected this summer, California officials are trying to assess the long-term economic impact on workers and businesses — and what more can be done to protect workers bearing the brunt of extreme temperatures.

Although California is one of the few states with heat standards protecting outdoor workers, advocates and workers say enforcement is still a struggle. Meanwhile the state has been trying for years to create indoor workplace heat rules.

A 2021 study of California worker compensation data by a left-leaning economic research nonprofit shows hot days lead to increased workplace accidents across California. The Washington Center for Equitable Growth study estimates hot temperatures have caused at least 360,000 workplace injuries in California from 2001 to 2018, or about 20,000 injuries a year. 

The welfare impacts associated with heat-related workplace injuries may be on the order of $525 million to $875 million per year in California.

workplace heat study by the washington center for equitable growth

Researchers examined California workers compensation data and tracked daily temperatures down to the zip code. They compared the number of worker injuries and illnesses on 85-to-105-degree days to days when temperatures hovered around 60 degrees. 

A new state advisory committee is set to use this data as a roadmap to tackle hot workplace issues. The group of state agency staffers and scholars will examine persistent problems with underreported heat-related illness and injuries, as well as gaps in data collection and the financial toll on workers and businesses when temperatures rise and production falls.

Young workers at risk

A day above 100 degrees can lead to a 10-15% increase in same-day injuries on the job, the study says, with injuries hitting low-wage workers hardest. And recovering from a heat-related injury or illness costs the average worker $35,000, including health care and long-term wage impact.

“This implies that the welfare impacts associated with heat-related workplace injuries may be on the order of $525 million to $875 million per year in California alone,” the study authors wrote.

The study says workplace injuries include incidents not usually linked to heat, such as falling from heights, getting struck by a vehicle or mishandling dangerous machinery. Research links high temperatures to reduced cognitive performance and decision-making. 

The lead author of the study, University of Pennsylvania professor R. Jisung Park, is a member of the advisor committee. He and his coauthors found that low-wage workers, especially young men, face the greatest risks of heat injuries, even in mostly-indoor workplaces like restaurants or warehouses.

The state's advisory committee met for the first time at the end of June. Its mandate is part of a package of heat-related legislation passed last year. 

Gov. Gavin Newsom in September signed several bills creating the first extreme heat warning and ranking system in the nation, directing the California Department of Public Health to study the impact of extreme heat on pregnant workers and encouraging local governments to invest in protections against extreme heat and other climate effects. 

“There are certain sectors that are going to be heavily influenced of course, including food production,” said Daniel Sumner, an advisory committee member who is an agricultural and labor economist at UC Davis. “I think we’d be remiss not to try to think through impacts that directly affect workers’ lower productivity, raise danger for workers, and as a consequence raise food prices.”

Are California workers protected from heat?

California is one of a few states with laws that mandate employers provide water breaks, shade and rest for outdoor workers once temperatures reach certain levels. 

The state implemented its outdoor heat standard in 2005, after several farmworkers – three in Kern County and one in Fresno County – died due to heat exposure. After the 2008 death of a pregnant teen working in a Central Valley vineyard drew national outrage, state officials frantically tried to strengthen and enforce the heat protections.

The Washington Center study found occupational heat-related injuries in California declined by about 30 percent since the standards took effect in 2005.

There still are no heat-related federal workplace protections, even for outdoor workers, although the Occupational Health and Safety Administration announced two years ago it was developing heat rules for outdoor and indoor workers.

There’s currently little relief for California’s indoor workers. The state has been considering proposals for heat rules for employees in indoor settings like restaurants or warehouses for nearly seven years, missing a 2019 deadline the Legislature set.

Last summer, a 24-year-old United Parcel Service driver died after collapsing from the heat during deliveries in Pasadena. 

The 340,000-strong union representing the UPS workers has been seeking heat rules that would cover its California members. The union reached a "historic" contract agreement with the company July 25 after threatening a strike, securing a deal with higher wages and more heat protections.

Jassy Grewal, a lobbyist for the United Food and Commercial Workers Western States Council and a member of the state’s heat advisory committee, said workers in high-intensity environments, or those who don’t have a cool place at home, are especially vulnerable without indoor heat rules.

“What type of pressures from employers, like work quotas, contribute to heat-related illness,” Grewal asked during the first committee meeting. “And how does the intensity of work and how physically demanding it is relate to the impact of heat exposure while at work and while not at work?” 

Gaps in job protections

Unions and worker advocates have sued the state in the past to enforce heat-related regulations, and they say the state needs to hold employers accountable. 

Advocacy groups warn that despite progress, the greatest risk to workers lies with the state’s troubled enforcement record. 

Some experts say it’s as simple as better outreach, informing workers about heat risks and their rights.

“It's all implementation and ensuring that these workers actually get the benefits of these laws,” said Michael Méndez, environmental policy professor at UC Irvine, “and having a culturally and linguistically appropriate messaging on the risk and severity of these heat waves. 

“I think for any population it's confusing to understand how our climate is changing and how much risk they could have. So ensuring that we have trusted messengers and doing it in a culturally and linguistically appropriate way matters.”

“We expect state agencies to be out in full strength across California to make sure employers are being compliant with the state heat rules. Heat is still a deadly hazard.”

Antonio de Loera-Brust, UFW spokesperson

The United Farm Workers sued the Cal/OSHA in 2012 to compel the state to enforce heat rules for farmworkers. In 2015 the state settled a suit the union brought on behalf of five farmworkers who alleged CalOSHA was systematically neglecting its duty to enforce the 2005 law. 

UFW spokesperson Antonio de Loera-Brust told CalMatters “people died to win” California’s enforcement standards. 

“We expect state agencies to be out in full strength across California to make sure employers are being compliant with the state heat rules,” De Loera-Brust said. “Heat is still a deadly hazard.”

Farmworker health

A February study on California farmworker health and safety by the UC Merced Community and Labor Center found that only a third of farm laborers could recognize the symptoms of a heat-related illness. 

Only half of the roughly 1,500 farmworkers surveyed said their employers always provide shade mandated by California law when it hits 80 degrees, while a quarter said their employers never or rarely provide the required shade.

The study, which surveyed farmworkers in six languages, also found:

• About 22% of farmworkers said their employer “never” monitors for heat illness. A slightly higher percentage in the Imperial Valley, where scorching temperatures are common, said the same. 
• 82% of farmworkers in the San Joaquin Valley said they have received heat related illness training.
• About 43% of farmworkers statewide, including two-thirds of Central Coast farmworkers, said their employers never had a written heat illness protection plan. 

Some farm employers still don’t comply with state rules about providing water, shade and rest, the survey shows.

• 55% of farmworkers across the state said their employers always monitored the temperature on hot days — 76% said it in the Imperial Valley, but 46% did in Napa Valley and Sonoma areas. 
• 75% of farmworkers said their employers provide clean drinking water every time.
• Barely half of farmworkers reported their employers always provide a 10-minute cool down rest, while 21% said their employers “never” did. 

Alice Berliner, worker health and safety program director at the community and labor center, said it’s clear employers some workers aren’t getting safety information or training in Spanish when they need it. 

“We know heat-related deaths are going up,” she said. “If we want to prevent future deaths from happening, we really need to ensure workers are protected at work.”

State officials taking preventive measures, such as conducting heat sweeps ahead of  heat waves, has helped, she added. 

What will the state committee do?

Assembly Speaker Robert Rivas, who authored legislation creating the advisory committee last year, called the panel of 13 a “solid first step.” He said he will work with the Legislature to do more for workers.

“Climate change is accelerating, and extreme heat and heat-related illnesses are on the rise,” the Salinas Democrat said in a statement. “California is committed to protecting workers’ health and quality of life during extreme heat waves.”

Despite near-universal consensus among state officials and advocates that heat reform work is urgent, and despite recent record shattering temperatures, the committee has been given a 2026 deadline to report results to the Legislature.

The committee is set to meet quarterly. The next session is September 19. Members indicated they’ll likely commission a study to guide the committee’s work.

“I have no doubt the work this committee will do will save lives,” said Cal/OSHA chief Jeff Killip at the meeting.