Tables? There's two reasons: you're hiding the data or you don't want to follow up.
As Arizona's summers grow more punishing, the state has trained its gaze on the dead while the living — those flooding emergency rooms in record numbers — remain poorly understood. Between 2020 and 2024, heat-related hospital visits more than doubled, yet the data collected on those patients is so incomplete and so passively presented that it cannot answer the most basic questions about who is suffering and why. Public health experts argue that Arizona's heat crisis is, at its root, a crisis of housing and mental illness — and that until the state learns to read its own hospital data as a call to structural action, cooling centers and water stations will remain gestures rather than solutions.
- Heat-related emergency visits more than doubled in four years, yet the state report meant to capture this surge offers tables where there should be analysis and vague targets where there should be strategy.
- Critical data on homelessness, occupation, and the location of heat exposure is missing for the vast majority of cases, leaving policymakers unable to identify which neighborhoods, jobs, or populations need intervention most urgently.
- Requests from journalists for the underlying hospital spreadsheets went unanswered, and state officials deflected accountability by claiming correlations between heat illness and housing or drug use simply cannot be made — a claim experts flatly reject.
- Arizona ranks 49th in psychiatric hospital capacity while more than half of its estimated 14,000 homeless residents live with serious mental illness, yet less than 0.02 percent of the state's Medicaid budget flows toward supported housing for this population.
- Advocates are pushing the state to cross-reference hospital data with housing, mental health, and workplace records — a shift that is beginning, slowly, to appear in updated policy language, though without the concrete action steps that could save lives.
Arizona's emergency rooms are absorbing a heat crisis that the state's own data cannot fully explain. Between 2020 and 2024, heat-related emergency visits more than doubled and hospital admissions climbed 60 percent — figures captured in a May report from the Arizona Department of Health Services. But the report, experts say, tells almost none of the story that matters.
For years, Arizona has organized its heat response around a single metric: deaths. That focus produced some results — 2024 saw a modest decline in heat fatalities — but it also drew attention away from the richer, more actionable information embedded in hospital records. Will Humble, who led the state health department for six years and now heads the Arizona Public Health Association, reviewed the report and found it more concealing than revealing. The document runs twenty pages of tables with no graphs, no policy recommendations, and no narrative thread. "Tables," Humble said, "are what you use when you're trying to hide the data or don't want to follow up on it."
The gaps are significant. The report identifies comorbidities and demographic patterns — men, young adults, and patients with mental illness appear disproportionately — but says almost nothing about why. Homelessness goes unmentioned as a risk factor despite strong circumstantial evidence of its role. Data on what activity preceded a patient's arrival is missing for 87 percent of emergency visits. Information on where heat exposure occurred is absent for one in five cases. Without these details, the state cannot determine which occupations, neighborhoods, or communities need help most.
Humble has long argued that Arizona's heat crisis is fundamentally a crisis of housing and mental health. More than half of the state's estimated 14,000 homeless residents have serious mental illness — nearly 8,000 people with nowhere to shelter when temperatures exceed 120 degrees. Arizona ranks 49th nationally in psychiatric hospital capacity, and less than 0.02 percent of its $5.3 billion Medicaid budget goes toward a housing trust fund for people with serious mental illness. "The most important thing, if you really want to make a dent in this problem, is permanent supported housing," Humble said. "But they just want to talk about water stations."
When the Arizona Republic requested the full hospital data in June, the state never responded. Officials later said that hospitals don't collect housing or drug use information, making correlations "not possible" — a claim Humble dismissed, noting the state could easily overlay existing data from other agencies. It has simply chosen not to.
Signs of incremental progress exist: the state's 2025 heat preparedness update mentions mental health twelve times, up from five the year before. But for public health advocates, the pace is agonizing. "It's the lack of action steps that is just so frustrating, because people's lives are on the line," said Jill Guernsey de Zapien, a former University of Arizona public health official. Until Arizona learns to treat its hospital data as a map toward structural solutions rather than a record of managed crisis, the gap between what is known and what is done will continue to cost lives.
Arizona is getting hotter, and more people are ending up in emergency rooms because of it. Between 2020 and 2024, heat-related visits to Arizona emergency departments more than doubled—from 2,467 to 5,285 people—while hospital admissions for heat illness climbed 60 percent, from 990 to 1,578. These numbers arrived in a May report from the Arizona Department of Health Services, a five-year snapshot of a growing crisis. But the report itself, experts say, tells almost none of the story that matters.
For years, Arizona has focused its heat response on a single, grim metric: deaths. Phoenix's mayor and the governor have launched initiatives, county medical examiners have revised investigation protocols, and in 2024, the state reported a slight decline in heat fatalities for the first time in recent memory. The attention worked, in a narrow sense. But it also obscured something more useful: the data hiding inside those hospital visits and admissions, waiting to be analyzed, interpreted, and turned into policy.
Will Humble, who directed the Arizona Department of Health Services from 2009 to 2015 and now leads the Arizona Public Health Association, was blunt about what he found when he reviewed the state's hospital report. "I'm glad they did it," he said. "But we still need much more attention to the associated issues and more detail included in this report." The document runs twenty pages—mostly tables and summary points. By contrast, a single county's 2024 heat death report is longer and far more detailed. The state's hospital data, Humble suggested, was presented in a way that obscured rather than illuminated. "Tables? There's two reasons why you do tables: if you're trying to hide the data or if you don't want to follow up on the data," he said. "I'll give them the benefit of the doubt and say they were just lazy. But graphs are what tell stories."
The gaps in the data are substantial. The report notes which patients had heart conditions, respiratory disorders, or mental illness—conditions that made up more than 90 percent of hospitalizations. It shows that men accounted for 67 percent of emergency visits and 76 percent of admissions. It documents that young adults between 20 and 44 appeared most frequently. But it says almost nothing about why. The report makes no mention of homelessness as a risk factor, despite Humble's suspicion that a rise in unsheltered populations explains much of the shift in who is showing up in emergency rooms. Data on what activity preceded a patient's arrival is missing for 87 percent of emergency visits and 96 of hospitalizations. Information about where the heat exposure actually occurred is absent for 20 percent of cases. Without these details, the state cannot answer basic questions: Which occupations are producing the most cases? Which neighborhoods? Which populations need help most urgently?
Jill Guernsey de Zapien, a former associate dean for community programs at the University of Arizona's college of public health, appreciated that the state released the report at all. But she echoed Humble's frustration. "How does this data help us to define action steps geographically and for population groups?" she asked. "How does it help us to identify policy initiatives and points of action?" The state's more recent recommendations for updating its heat preparedness plan include just two references to hospital data and a vague goal to "stabilize" emergency visits by mid-2026—a target copied from the previous year's plan with no analysis of progress or strategy for achieving it.
The missing analysis points toward missing solutions. Humble has spent years arguing that Arizona's heat crisis is fundamentally a crisis of housing and mental health. More than half of the state's estimated 14,000 homeless people have serious mental illness—nearly 8,000 individuals with nowhere to go when temperatures exceed 120 degrees. Arizona ranks 49th in the nation for psychiatric hospital capacity. Yet the state's heat response emphasizes cooling centers and water stations rather than permanent supported housing or mental health services. A 2024 report from Arizona's Medicaid agency revealed that less than 0.02 percent of its $5.3 billion budget went to a housing trust fund for people with serious mental illness. "Probably the most important thing if you really want to make a dent in this problem is that you've got to have more permanent supported housing for people with a serious mental illness," Humble said. "But they just want to talk about water stations."
When the Arizona Republic requested the full spreadsheets of hospital data in early June, the state's automated system promised a response within ten business days. The newspaper never received the data. Without access to the underlying numbers, understanding of how heat is showing up in Arizona hospitals remains limited to what the cursory state report included. The state's media relations coordinator responded to concerns about the report's shortcomings by saying hospitals do not collect information on housing status or drug use, making it "not possible" to analyze correlations between heat illness and these factors. But Humble pointed out that this analysis is easily possible: the state could simply graph existing data on homelessness, drug use, and mental health from other agencies alongside the hospital numbers. It has not done so.
As Arizona becomes a national symbol of the human cost of extreme heat, advocates are pushing the state to connect the dots between hospital data and the root causes of heat vulnerability. The work has begun—the state's updated 2025 recommendations mention mental health twelve times, up from five in the previous year, and cooling centers are discussed less prominently. But for Guernsey de Zapien, the pace of change is agonizing. "It's the lack of action steps that is just so frustrating, because people's lives are on the line," she said. Without a fundamental shift in how the state analyzes and acts on hospital data, Arizona will continue treating heat illness as a crisis to manage rather than a problem to solve.
Notable Quotes
We still need much more attention to the associated issues and more detail included in this report.— Will Humble, former Arizona Department of Health Services director
It's the lack of action steps that is just so frustrating, because people's lives are on the line.— Jill Guernsey de Zapien, former associate dean for community programs at University of Arizona's college of public health
The Hearth Conversation Another angle on the story
Why does it matter that the state released a report on hospital data if the report itself doesn't tell us much?
Because the data exists. It's sitting there in spreadsheets. The state has documented 5,285 emergency visits and 1,578 hospitalizations in 2024 alone. If someone actually analyzed that—looked at which neighborhoods, which occupations, which populations—you could start to see where to intervene. Instead, the report just presents numbers in tables and moves on.
But the state said it can't analyze things like homelessness or housing status because hospitals don't collect that information.
That's technically true, but it's also a dodge. Other agencies have data on homelessness, mental illness, drug use. The state could overlay that data with the hospital numbers. It's not hard. They just haven't done it.
So what would change if they did?
Everything. Right now, the state's heat response is cooling centers and water stations. But if you could show that half the people in emergency rooms are homeless or have serious mental illness, suddenly the conversation shifts to housing and mental health funding. That's where the real solution is.
Why hasn't that happened?
Partly because heat deaths get headlines and hospital visits don't. Deaths are a number people understand. But also because connecting those dots requires admitting that the state's response has been incomplete. It's easier to keep doing what you're doing.
Is there any sign that's changing?
A little. The state's newer recommendations mention mental health more often. But it's slow. And people are still dying in the heat while we wait for the state to analyze data it already has.