Maricopa County, which includes Phoenix, is known as the Valley of the Sun by the 4.5 million people who call it home. The name fits. Phoenicians braved 22 days above 110 degrees in 2022. Brutal heat is nothing new here, but it’s only getting worse: The number of days above that dangerous threshold is projected to double by 2060. “Phoenix is very much on the front lines of climate change,” says city councilmember and Grist 50 honoree Yassamin Ansari, who has made climate central to her platform.

Maricopa County recorded 339 heat-related deaths in 2021, continuing an upward trend that started in 2014, when 61 people died, and has climbed 70 percent since 2019. As the body’s core temperature rises, the risk of heat stress or heat stroke increases. Once the body’s internal temperature hits 103 degrees, the brain, lungs, heart, and key organs can’t function properly.

Heat season was revving up when Ansari was inaugurated in April 2021, but so too was the city’s response. Six months after Ansari took office, Phoenix established a $2.8 million Office of Heat Response and Mitigation — the first, and so far only, publicly funded office of its kind. Most cities spread such responsibilities across departments, but heat is the agency’s sole focus. Its four employees are charged with preventing deaths and lowering urban temperatures, which they hope to achieve through initiatives as simple as handing out bottled water and as ambitious as doubling the city’s tree cover.

“Our ultimate goal,” says Ansari, “is to save as many lives as we can.”

Take a look at Maricopa County’s annual heat death reports and a consistent pattern emerges. “The people most likely to die from heat exposure are disproportionately likely to either be unsheltered or live in mobile homes,” says Lora Phillips, a sociologist at Arizona State University.

Those in lower-income communities of color that have faced historical disinvestment also tend to live with fewer trees and more concrete, which traps heat. With every $10,000 increase in a neighborhood’s annual median household income, Phoenix residents enjoy a decrease of .50 degrees Fahrenheit in daytime surface temperature. “You don’t even need to read reports. You can just drive around and you see what neighborhoods are 10 degrees warmer than others,” says Melissa Guardaro, an expert in sustainability and resilience at Arizona State University.

Carrillo, who also is a community organizer, says this blatant inequality creates an “infrastructure of failure” that is passed down through generations. “Why are the kids not outside?” he says. “It’s because their communities are not built for them to be outside.”

Read the full article about heat equity by Emma Loewe at Grist.