When a team of University of Miami researchers started taking a closer look at who in Miami is most at risk from dangerous heat, they were surprised to find a complicated balance some households strike, even ones with moderate incomes, to keep the air conditioning running.
“ It's not necessarily just the case that it's the classic, low-income renter,” said Lynee Turek-Hankins, the study’s lead author. “It's a more widespread issue than people realize.”
In one pleasant, tree-lined neighborhood, Turek-Hankins said, she was surprised to find a household with a functioning air conditioner that couldn’t afford to keep it running.
“This was a lower-medium-income household that on paper did not look like who we might consider burdened but was just above some of the income thresholds to qualify for certain programs,” she said.
At another, the resident only cooled the house when his children came to visit.
As Miami-Dade nears the start of its annual heat season in late May, the study provides a more nuanced look at heat threats. Historically, the region has not been considered as risky as parts of the Midwest or Northwest because so many homes have AC. But climate change and high housing costs are altering that calculus and in ways making the problem more chronic, putting a growing number of people, particularly outdoor workers, at risk.
A vulnerability assessment conducted by Miami-Dade in 2022 looked at risks by ZIP code by analyzing heat-related hospitalizations, tree cover, concrete or pavement, day and night temps, and areas with more outdoor workers. The county also looked at groups more likely to be vulnerable according to census data: older people, those with less education, lower incomes, or residents of mobile homes or living alone. The maps highlighted with color codes those areas most at risk.
But the researchers wanted to test some of those assumptions. So working with Catalyst Miami, they went looking for households that said they were suffering from excessive heat.
After an initial round, and to ensure they were getting a mix of households — apartments as well as single family houses, younger residents and families along with seniors — the research team created fliers and posted them at libraries and community centers. The team also reached out to a network of foster families, Turek-Hankins said. It ended up with 57 households willing to let the team install monitors, disclose details about their finances and undergo extensive interviews.
Visiting people in their homes, Turek-Hankins said, was key to the findings.
“There's a completely different experience when you're sitting in their living room, on their couch, talking with them for an hour, an hour and a half, and being like, yeah, I feel really hot right now trying to have this serious conversation with you, and it's actually a little bit hard for me to focus,” she said.
The reasons the houses became too hot — households are considered too hot when temperatures climb above 82 degrees — were varied. Some had poorly functioning AC units they couldn’t afford to fix. Others kept them off because bills were too expensive. Others said to keep the AC on they sometimes skipped medical appointments or scrimped on groceries.
“ People have to give up really meaningful things sometimes to be able to afford those energy bills,” she said.
Come summer, Turek-Hankins said she expected to find the homes hot. But she was surprised by just how hot. In six of the homes, the average temperature inside was higher than outside in July and August. In 10 households, cooling costs amounted to a tenth of their incomes.
“So just the severity issue was really shocking,” she said. ”We're not really talking about a hurricane, and maybe you don't have [air conditioning] for a day or two. We're talking about people dealing with this for the entire season.”
And with climate change driving up already warm temperatures, even a fraction of a degree can change risks to health and sicken healthy people, or exacerbate underlying problems like heart disease or asthma. To reflect that risk, the National Weather Service’s Miami office lowered the threshold in Miami-Dade and Broward counties for issuing heat advisories because humidity can drive up the feels-like temperature.
This month, the weather service also changed the wording of heat advisories to simplify the threat. It now calls them extreme heat warnings and watches, rather than excessive.
The findings in the study, Turek-Hankins said, show problems can be fixed with existing programs — like providing AC units or assistance paying bills. But how those programs reach the public needs to be tweaked, she said.
“It's just a matter of retooling and expanding or changing some of the things that are in existence. It's not about, necessarily, a revolution,” she said.
What Miami reveals about living with heat could also be applied to other places in the Southeast that experience the same kind of humid heat, she said. Another researcher who worked on the project is near completing another study that looks at impacts from chronic heat.
“When we're measuring these things, it might not look a certain way all the time,” she said. “If we can expand our understanding of who is dealing with this issue and why they're in the predicament that they're in, it'll make it less of a taboo subject.”
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