Each year, heat-related illnesses send more than 67,000 people nationwide to the hospital and kill more than 700.

As climate change brings longer, stronger and more frequent heat waves, a new study by Centers for Disease and Prevention, Arizona State University, and the Maricopa County and Arizona health departments looks at the effectiveness of cooling centers in Maricopa and Yuma counties.

Heat exposure and illness rates in Maricopa and Yuma counties rose from 2010-2020, especially among people aged 65 or older.

Air-conditioned cooling centers can provide refuge, especially for vulnerable populations, who are unduly affected by heat-related illnesses. They include those experiencing homelessness, nonnative English speakers, people with limited financial resources, outdoor workers, communities of color, people with mental health disability or chronic medical conditions, those without access to air-conditioning, older adults and children.

But survey data suggest many are unaware of, or unable to access, them due to communication and transportation barriers.

Of the 39 residents aged 65 and older surveyed in Yuma County, 26% said they felt their health was endangered on very hot days, 15% always or sometimes felt too hot at home, and 44% reported experiencing heat-related medical symptoms during the past year. Overall, 54% of said they knew what a cooling center was, and 36% knew where to find one in their area.

In 2019 and 2020, high vulnerability areas housed roughly half of Maricopa County's cooling centers and 60 to 83% of Yuma County's.

The authors recommend opening more cooling centers, increasing hours and offering multilingual materials.