DAVID GREENE, HOST:
This summer, volunteers are going to be fanning out in 13 cities across the United States to literally take the temperature of their neighborhoods. They're driving cars that are equipped with special sensors to create these heat maps. This is part of a project to help cities protect people as the world gets warmer. Mose Buchele from member station KUT reports from Austin.
(SOUNDBITE OF STREET AMBIENCE)
MOSE BUCHELE, BYLINE: Like much of Austin, the Dove Springs neighborhood was built for the car - lots of single-family homes, four-lane streets and strip malls. This is a Hispanic and working-class part of town, says Frances Acuna.
FRANCES ACUNA: It's not middle income. They're low. Some of them are lower than low income.
BUCHELE: Acuna's a community organizer working on public health. She's lived here over 20 years, and she's noticed it's getting hotter, even worse than the usual summer-in-Texas hot. Records back that up. And the last couple decades, long stretches of triple-digit days have become common. Nights aren't cooling down like they used to.
ACUNA: I was noticing yesterday, as soon as I got out, it was like the heat was penetrating into my skin.
BUCHELE: A big part of this is climate change. But in cities, the asphalt and concrete are making it worse. They absorb heat, then radiate it back into the air. It's called the urban heat island effect, and even within cities, it can change the temperature by 10 to 15 degrees in a matter of blocks. It's often lower-income parts of town that are the hottest. So for Acuna, this is an environmental justice issue.
ACUNA: Because we have more asthma cases, we have more respiratory infections, and I believe all this has to do with the heat.
BUCHELE: That's why she's agreed to make three drives through Dove Springs to measure it.
MARC COUDERT: So pick out a sensor.
BUCHELE: Austin city staffer Marc Coudert hands out the sensors, which get attached to the side of a car.
COUDERT: They stick out like snorkels, I guess you could say.
BUCHELE: Coudert says cities usually use satellites to map hot spots. The problem is that they measure ground temperature, not heat index, so places like parking lots and airports show up hottest. With these sensors, 12 volunteers will create detailed heat maps where people really live.
COUDERT: So the routes are very, very specific but very confusing if you were to just look at them.
(SOUNDBITE OF STREET AMBIENCE)
BUCHELE: Frances Acuna is driving with a friend to help navigate. I couldn't join because of the pandemic. So I gave a call instead.
(SOUNDBITE OF PHONE RINGING)
ACUNA: (Speaking Spanish). Hello?
BUCHELE: Hello, Frances. How are you doing?
ACUNA: Right now it's pretty quiet. And, of course, it's very hot. It's 3:30, so this is the heat hour.
BUCHELE: It's hitting triple digits. As she drives, she sees things that make that worse.
ACUNA: There's a bus stop right here with no shade structure.
BUCHELE: She often sees neighbors waiting there in the sun.
ACUNA: Sometimes I give them a ride because, you know, I feel for them.
BUCHELE: She says on days like this, her son comes home from school dehydrated.
ACUNA: He's like red, completely red.
BUCHELE: Marc Coudert says the information Acuna and others are gathering will guide Austin's projects in underserved neighborhoods. These could be simple, like putting in trees and shade structures, more crosswalks to get people out of the sun faster. Or they could be more complicated.
COUDERT: And maybe it isn't structure. Maybe it's actually policies. Maybe it's how we set up times that places are open. Maybe it's understanding how people get from a grocery store home and have to take two buses rather than one. Maybe it's something we just haven't thought about yet.
BUCHELE: These highly detailed heat maps could also advance science.
HUNTER JONES: We don't really understand fully everything there is to know about urban heat islands yet.
BUCHELE: Hunter Jones is with the National Oceanic and Atmospheric Administration. He says researchers will use the maps to learn how urban heat interacts with climate change and what works best to combat it.
JONES: It would be interesting to go back and look at some a few years later to see how things may have changed both intentionally and unintentionally as the city has developed.
BUCHELE: In Austin, Frances Acuna says there's no time to lose for her community. If we don't do something about the heat now, she told me, it's going to get a lot worse.
For NPR News, I'm Mose Buchele in Austin.
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