California announces tool to protect at-risk communities from dangerous heat waves ahead of triple-digit temperatures

SACRAMENTO – California today announced the launch of CalHeatScore, a cutting-edge tool to forecast and rank heat severity risks and link Californians with available resources to stay safe during extreme heat events.

CalHeatScore, developed by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA), brings together ZIP-code level data to provide locally tailored guidance. Specifically, the tool highlights vulnerable groups most susceptible to extreme heat, including older people, children, and outdoor workers. It also offers tips for staying safe—such as how to recognize signs of heat illness—and important resources, like locations of the nearest cooling centers. User feedback will drive refinements to the tool.

“Every single preventable death is one too many,” said Yana Garcia, California’s Secretary for Environmental Protection. “This groundbreaking tool will help Californians plan and respond so they can stay safe when a heat wave is about to strike. And it will shore up the state’s all-in fight against the very real dangers that climate change keeps bringing to our doorstep.”

Extreme heat is the leading climate-related health hazard in the state, claiming more lives annually than any other climate threat. Last year, California communities experienced the hottest summer on record in 130 years. According to a report from the Department of Insurance, from 2013 to 2022, seven extreme heat events resulted in nearly 460 deaths, over 5,000 hospitalizations and about 344 adverse birth outcomes.

“Health risks at 95°F are very different from those at 110°F, and even the same temperature can have vastly different impacts to public health in coastal areas compared to the Central Valley,” said OEHHA’s Chief Deputy Director Dr. David Edwards. “CalHeatScore’s localized approach ensures that every Californian has the tools and knowledge to protect themselves and their loved ones during dangerous heat events.”

OEHHA’s research shows a correlation between heat and a range of negative health effects, including death, lower birth weight, and increased emergency room visits and hospitalizations for conditions ranging from heart conditions to mental health. Extreme heat also takes an economic toll on the state, with an estimated $7.7 billion of lost wages, agricultural disruptions and power outages.

“CalHeatScore is an important tool to prepare Californians for extreme heat,” said Nancy Ward, director of the California Office of Emergency Services (Cal OES). “It helps increase our readiness for heat events and protect those at greatest risk.”

OEHHA will continue to evolve CalHeatScore, incorporating user feedback to ensure it reflects on-the-ground conditions and using the best available science to measure and communicate heat impacts.

“We invite Californians to join us in making CalHeatScore a tool that truly serves every community and reflects their real, everyday experiences with extreme heat,” said Dr. Edwards.

The first of six CalHeatScore informational webinars will be held on Thursday, June 12 from 12-1 p.m. Register for the Zoom. The webinar will provide background on CalHeatScore, examples of how to use the tool, and share an overview of the public engagement process. To learn more about CalHeatScore, visit calheatscore.calepa.ca.gov.

Background

Assembly Bill 2238, authored by Assembly member Luz Rivas and signed into law by Governor Gavin Newsom in 2022, was the impetus for developing CalHeatScore. This landmark bill built upon the 2021 recommendation by the California Department of Insurance’s Climate Insurance Workgroup to develop a heat wave-ranking system.

OEHHA collaborated with key state agencies, including the California Office of Emergency Services, Governor’s Office of Land Use and Climate Innovation, Department of Insurance, and Department of Public Health to ensure CalHeatScore is a scientifically robust and public health-centered tool. OEHHA also worked with the UCLA Center for Healthy Climate Solutions to develop the data and methods behind CalHeatScore.

The Office of Environmental Health Hazard Assessment (OEHHA) is the lead state agency for the assessment of health risks posed by environmental contaminants. OEHHA’s mission is to protect and enhance the health of Californians and our state’s environment through scientific evaluations that inform, support and guide regulatory and other actions.