SACRAMENTO, Calif. — As California braces for another dry and hot summer, state legislators are proposing a law that alerts residents to extreme heat with rankings about their severity.

AB 2238 would create advance warnings for heat waves similar to existing systems for hurricanes, tornadoes and wildfires.


What You Need To Know

  • AB 2238 would create advance warnings for heat waves similar to existing systems for hurricanes, tornadoes and wildfires

  • Extreme heat in California is expected to increase because of climate change 

  • Extreme heat increases the risk of death among seniors, children and individuals with chronic medical conditions

  • If AB 2238 passes, California would be the first state in the nation to have an extreme heat ranking and warning system

“We know ranking and better warning of heat waves will keep people safer,” California Insurance Commissioner Ricardo Lara told Spectrum News 1.

Introduced in February, AB 2238 received a letter of support from a coalition of California doctors this week that underscored the health implications of extreme heat.

Total mortality increases 8% on the hottest days during an average Los Angeles summer, the letter said, with consecutive days of intense heat causing as many as 30% more deaths. Seniors, children and individuals with chronic medical conditions are most at risk, as are outdoor workers, individuals in low-income communities and Blacks and Latinos.

“We can do much more to protect everyone from the heat and especially those most vulnerable,” said the letter, which was signed by doctors representing Stanford University, the University of California-San Francisco School of Medicine and the UCLA Center for Healthy Climate Solutions, among others. “We have been ranking and naming other natural disasters for decades because it has been shown to increase public awareness and improve coordinated responses.”

Advance warning systems for hurricanes, tornadoes, wildfires and other extreme weather events have long provided notice to people and businesses, giving them a chance to escape from harm.

AB 2238 cites California’s “red flag” wildfire warnings and the National Oceanic and Atmospheric Administration’s tropical storm naming system as providing valuable templates for an extreme heat ranking system.

Exactly how the extreme heat ranking and warning system will function has not yet been determined, but California Assemblymember and AB 2238 co-author Luz Rivas said it could be a number system, as used with hurricanes, with higher numbers indicating more severity, or a color system, as used with fire danger, with red indicating the most dire conditions.

What sorts of response those numbers or colors would prompt could be a mix of individual responses, Rivas told Spectrum News 1. It could mean telling people to stay indoors or it could prompt governments at the local level to issue a state of emergency.

AB 2238 was born from Lara’s California Climate Insurance Working Group, which he created in 2019 after taking office. Bringing together insurance experts and environmentalists, the group found wildfires, flooding and extreme heat presented major climate threats to the state and recommended solutions to reduce their impact.

One of the group’s proposals was “ranking heat waves to provide levels of risk and more specific warning to protect our most vulnerable communities,” said Lara, who approached Assemblymember Rivas with the idea last November at the United Nations Climate Change Conference.

AB 2238 is working its way through the legislature as the National Oceanic Atmospheric Administration says temperatures are leaning above normal for much of the state through at least July of this year. Already, California has logged some of its highest temperatures in history. In 2020, parts of LA County hit a record-breaking 121 degrees, while in 2021, the Coachella Valley hit an all-time high of 123 degrees.

A Climate Vulnerability Assessment from the LA County Sustainability Office last month found that extreme heat events are expected to increase tenfold from about once every other year to twice a year by 2050. The U.S. Centers for Disease Control defines extreme heat as summer temperatures that are much hotter than average.  

California law requires the state’s Environmental Protection Agency to identify the extent and severity of urban heat islands so cities can set goals to bring down the temperature. The state also requires the Insurance Commissioner to look at ways of reducing the risks of climate change.

AB 2238 would require the California EPA to develop a statewide extreme heat ranking system by Jan. 1, 2024, and to submit a study about the costs of past extreme heat events to the Integrated Climate Adaptation and Resiliency Program, which is tasked with coordinating local efforts to adapt to the impacts of a warming planet.

The agency would then need to develop a plan to communicate extreme heat rankings to the public with the Office of Emergency Services and other relevant agencies and organizations and develop guidelines for local governments to plan for extreme heat events.

A companion bill, AB 2076, would create a Chief Heat Officer and Extreme Heat and Community Resilience Program for the state to coordinate preparedness and response efforts and to support more localized plans. Rivas said she is in conversation with the state’s Natural Resources Agency to determine how the two bills will work together.

AB 2238 direct the state’s Department of Insurance to look at government and academic data on maximum and minimum temperatures and the durations of extreme heat events. It will also look at the historical health impacts of heat.

“We know heat waves have impacts on insurance, particularly health insurance when people get sick, and business insurance when we have blackouts,” Lara said.

Already, his office knows that “people without health insurance, or who are underinsured, are going to have a harder time recovering from extreme heat waves.”

AB 2238 would allow Lara’s office to better understand the economic consequences of extreme heat, including its effects on emergency room visits, construction, energy costs and liability insurance.

“These things are all interconnected,” Lara said.

By 2036, the average outdoor worker in the state risks losing six days of work annually because of extreme heat — or $740 per year, according to the Union of Concerned Scientists Too Hot To Work Report released last year. That has implications for multiple industries, including health care and insurance.

About 3.8 million people, or 21% of California’s total labor force, work outdoors. Construction workers, police officers, firefighters and those working in installation maintenance and repair jobs are most vulnerable to extreme heat, the study found, with workers in Riverside, San Bernardino and Imperial Counties feeling the worst effects.

With extreme heat days expected to quadruple between now and 2065, outdoor workers in Riverside County risk losing 25 workdays a year by midcentury and 39 by late century because of extreme heat, compared with 9 days historically, the report found. Workers in Imperial County risk losing 48 work days by midcentury and 65 by late century, compared with 18 days historically.

Many of the California lawmakers who co-authored AB 2238 represent areas most affected by extreme heat, including Rivas, who represents LA; Assemblymember Eduardo Garcia, who represents the Coachella Valley; and Assemblymember Joaquin Arambula, of the Central Valley.

AB 2238 has cleared two committees since its introduction earlier this year. The State Assembly Appropriations Committee is currently considering the legislation, after which it will go to the full Assembly for a vote before heading to the Senate. If passed, California would be the first state in the country to rate extreme heat events.