LAWRENCE — A new paper from researchers at the University of Kansas looks at extreme heat events in the United States, arguing a combination of inadequate data and unclear delineation of responsibility among government agencies leaves the nation unprepared for a hotter climate.
“We examined extreme heat events, such as heat waves, which are the deadliest form of meteorological disaster in the United States,” said co-author Nathaniel Brunsell, director of the Environmental Studies Program and professor of geography & atmospheric science at KU. “While public perception focuses on tornadoes or hurricanes, heat waves consistently cause more fatalities. The research aims to better understand how cities respond to these events and which populations are most vulnerable. A central argument is that effective response requires reliable data and a clear understanding of responsibility across different levels of government.”
The research appearing in the Journal of Climate Change and Health combines atmospheric science with policy analysis, according to the KU investigators.
“It draws on expertise in climate science, urban heat measurement, and public policy to address both the physical and social dimensions of extreme heat. This interdisciplinary approach reflects the complexity of the issue, which spans environmental, political and public health domains,” he said.
Brunsell said a key finding is the lack of a consistent, nationwide framework for responding to heat events.
“Responsibility varies widely depending on location, with no standard assignment to federal agencies, state governments or local municipalities,” he said. “This inconsistency has become more pronounced in recent years as shifts in federal policy have altered the availability of services and created uncertainty about legal authority. As a result, responses to extreme heat are uneven and often dependent on local capacity rather than a coordinated national strategy.”
Cities are generally responsible for developing heat-action plans, he said, which outline how they will respond to extreme heat events.
“Unlike other disasters, which often prompt reactive measures such as evacuations or shutdowns, heat requires both proactive and sustained responses,” Brunsell said. “These include opening cooling centers, issuing warnings and providing transportation for vulnerable populations. However, many cities rely on existing infrastructure and lack the resources to fully implement comprehensive plans.”
Oftentimes, local action plans are hampered by a lack of funds and budget priorities that can shift with elections and changing administrations.
“Effective heat response does not necessarily require federal mandates, but it does depend on consistency and adequate funding,” Brunsell said. “Local governments are often best positioned to implement solutions, but they frequently lack the resources to do so. Fluctuating federal policies further complicate implementation, creating uncertainty and limiting long-term planning.”
What’s more, the toll on human lives of heat waves in the U.S. is little understood because of major discrepancies in how heat-related deaths are recorded between localities, said Brunsell.
“In some areas, deaths are carefully documented by trained medical professionals, while in others, reporting may fall to elected officials without medical expertise,” he said. “Additionally, some jurisdictions frequently classify deaths as heat-related, while others rarely do so. This inconsistency makes it difficult to accurately measure the true impact of heat waves or track trends over time, even as meteorological data clearly shows that extreme heat events are becoming more frequent.”
Brunsell’s colleagues were lead author Noah Ring, a KU doctoral student in atmospheric science, who led much of the urban heat island analysis using remote sensing and neighborhood-level risk assessment, and Dorothy Daly, KU professor of environmental studies and public administration, whose research focuses on climate policy.
According to the researchers, while scientists agree on how to measure heat waves — and see heat waves increasing in frequency and severity from a climatological perspective — their actual impact on the lives of Americans is harder to measure, analyze and predict.
“Translating those climatological findings into human outcomes is far more difficult due to inconsistent data collection,” Brunsell said. “This gap complicates efforts to understand how extreme heat affects mortality and public health, limiting the ability to develop effective interventions.”
Brunsell said certain communities — like those with low incomes — have fewer means, like air conditioning, to cope with heat events. The KU researchers urged data collection that could help policymakers understand which populations are most at risk when temperatures rise.
“The impact of heat waves varies significantly across communities,” he said. “Factors such as income, race, occupation and access to education all influence vulnerability. For example, individuals working outdoors or without access to air conditioning face much higher risks than those in climate-controlled environments. Even within a single city, different neighborhoods can experience vastly different outcomes during the same heat event. Targeting limited resources effectively requires detailed knowledge of these disparities.”