California is facing a dangerous holiday heat wave that will see millions of people face triple-digit temperatures, and state and federal officials are vowing to do more to address the growing threat of extreme heat and its rising costs.

On Tuesday, the U.S. Department of Labor's Occupational Safety and Health Administration (OSHA) announced it would advance a national bill to protect indoor and outdoor workers from high temperatures. If passed, the regulation would set temperature-based standards for an estimated 35 million workers in warehouses, kitchens, farms and construction sites.

The proposal, which has been in the works since 2021, would apply to workplaces where the heat index regularly rises above 80 degrees, according to senior administration officials. It would follow similar steps from California, which in 2006 became the first state in the country to introduce permanent heat protection measures for outdoor workers and approved heat regulations for indoor workers just last month.

Officials said such rules are necessary as extreme heat claims increasing numbers of lives and the country grapples with more frequent and severe weather events caused by climate change. Last year, the U.S. experienced 28 disasters with damages of more than $1 billion, with total losses of more than $90 billion.

At the same time, the California Department of Insurance this week released a first-of-its-kind analysis revealing $7.7 billion in insurance losses related to extreme heat events over the past decade. The report quantifies the uninsured and insured costs of seven recent extreme heat events in the state and underscores the need for adaptive strategies.

It joins a growing body of evidence of the consequences of extreme heat – from increasing heat-related illnesses and deaths to impacts on biodiversity, economic impacts, agricultural losses and damage to infrastructure. Heat has caused more deaths over the past 30 years than hurricanes, floods and tornadoes combined, making it the deadliest of all climate hazards in the U.S., according to the National Weather Service. Last year was the hottest year on record.

“Extreme heat is a silent, escalating disaster that threatens our health, economy and way of life in California,” said a statement from Insurance Commissioner Ricardo Lara. “This report brings to light the horrifying hidden costs of extreme heat events and underscores the urgency of our efforts to create a groundbreaking heat wave ranking and statewide early warning system. We must prioritize resilience efforts and innovative insurance solutions to protect our state from the growing impacts and financial risks of extreme heat.”

In fact, experts have been pushing for tighter monitoring of heat impacts for years. A 2021 Los Angeles Times investigation found that deaths from extreme heat in the state are chronically underestimated. Following that investigation, Governor Gavin Newsom signed a law establishing a heat wave ranking system similar to those used for hurricanes. The system is set to take effect by January 1, 2025.

In recent years, Newsom also launched an extreme heat awareness campaign, urban greening programs and other measures to prepare residents for and adapt to increasing heat, but this year's budget deficit has led to some of these programs being cut.

While the $7.7 billion cost associated with heat events is significant, the Insurance Department estimates that the actual cost is likely higher. While some types of insurance cover the costs associated with extreme heat — such as health insurance, workers' compensation and crop insurance — there are gaps that require new mechanisms and investments, the agency said. The state is currently facing a separate insurance crisis related to worsening wildfires.

Other costs associated with heat include labor productivity losses, which ranged from $7.7 million to $210 million per event, according to the report. Infrastructure repair costs due to heat-related damage ranged from $3.8 million to $35 million per event, with roads and rails primarily affected, while power outages during heatwaves had significant economic impacts of up to $230 million.

One of the heat events covered in the report – a sustained heat wave in September 2022 – pushed California's power grid to its limits and prompted an emergency text message from the state's energy providers urging residents to conserve electricity, narrowly avoiding a blackout.

As it later turned out, 395 Californians died in the same heat wave, state health officials said. They also reported that Latinos and people of working age between 25 and 64 were the worst affected.

The Department of Insurance report also highlighted how communities of color, low-income communities and vulnerable populations such as seniors and children are severely affected by extreme heat.

Jonathan Parfrey, executive director of Climate Resolve, said the report's admittedly conservative estimates were “nevertheless shocking”.

“A hot day is not just an inconvenience – for hundreds of thousands of Californians, extreme heat is a matter of life and death,” Parfrey said, adding that the loss in worker productivity alone should be a wake-up call for industry and policymakers. “The lesson here is that investing in cooling solutions today saves money and lives tomorrow.”

But strengthening workplace safety will also help save lives, White House officials said.

OSHA's proposed rule, which will be sent to the Federal Register and made available to the public for comment, would, among other things, require workplaces to establish heat illness and injury prevention plans that are evaluated at least annually, provide workers with access to drinking water and cooling areas, and respond to symptoms of heat illness and emergencies.

At temperatures of 90 degrees or more, additional protective measures would come into effect, including mandatory rest breaks and monitoring of symptoms.

States like California that already have heat regulations for workplaces would have to meet the federal minimum requirements but could go further, officials said. States like Florida and Texas — which have passed laws preventing cities or employers from setting heat regulations — would also have to comply with federal regulations or face significant penalties for violations.

The proposed rule joins other efforts by the Biden administration to address worsening heat and climate threats, including a new National Weather Service heat risk tool, cooling assistance programs for low-income households and expanded investments in trees and green spaces.

The Federal Emergency Management Agency (FEMA) also announced on Tuesday that it would provide $1 billion in funding for its Building Resilient Infrastructure and Communities program to help communities reduce their risk from disasters and natural hazards such as extreme heat, wildfires, droughts, hurricanes, earthquakes and floods.

The funding covers 656 projects across the country, including significant investments in disadvantaged communities, agency officials said.

However, FEMA continues to face pressure from environmental groups and labor organizations urging it to broaden its definition of “major disasters” to include extreme heat. Advocates say this would open up additional funding opportunities during heat waves and help states and communities better prepare for rising temperatures.

This year alone, FEMA and other federal agencies have responded to more than a dozen disasters, including devastating wildfires in New Mexico and historic floods in Iowa and Minnesota, officials said.

They are currently monitoring Hurricane Beryl, which became the first Category 4 hurricane on record in June, as well as the record-breaking heat expected to hit much of the country this week.

But heat waves continue to pose a particular danger: According to a new report by the US Environmental Protection Agency, the heat season now lasts an average of 46 days longer than in the 1960s.

In California, authorities warned that the heat wave could also lead to wildfires as the high temperatures coincide with fireworks, barbecues and other activities surrounding the Fourth of July. Power outages are possible in some Northern California counties, where temperatures could reach as high as 43 degrees, authorities warned.

Temperatures could reach as high as 43 degrees in parts of the Central Valley and Antelope Valley, while the Coachella Valley could reach 49 degrees and Death Valley could reach 51 degrees.

Meteorologists expect the heat wave to continue for several more days, with some parts of the Golden State unlikely to improve until early next week.