Heat is not classified as a natural disaster. Arizona officials say that needs to change

Near the brick gateway entrance of Steele Indian School Park in central Phoenix, first responders arrived to tend to a man who was found unconscious lying on the sidewalk. He was huddled between an iron fence and a palm tree, his personal belongings stacked in a shopping cart nearby.

It was one call of many during Phoenix’s historic heat wave last month, when temperatures reached 110 degrees or above for 31 days straight. Phoenix Fire said heat-related emergency calls are up about 20% over this time last year.

Long stretches of extreme temperatures can lead to deadly consequences for public health. In Maricopa County alone, more people are dying from heat each year than they are from any other extreme weather event across all 50 states.

Since 2013, the toll from heat deaths in the county has outpaced casualties from any single weather event in the same year, and trends show the gap is widening. Yet despite the significant loss of life and economic impacts caused by heat, the federal government does not classify heat as a major disaster. It's something local and state leaders are trying to change.

Last year heat killed 425 people in Maricopa County. Preliminary data provided by the Maricopa County medical examiner's office suggests this year’s heat will be deadlier than last. According to the county health department’s weekly heat report, as of Aug. 31, there were 180 confirmed heat deaths, with 330 still under investigation.

In July alone officials suspect heat and the prolonged month-long heat wave were responsible for 290 deaths, including 23 people who likely died from heat on a single day, July 20, when temperatures reached 119 degrees.

Heat is not seen as a natural disaster, but local and state leaders want to change that

In September 2022, Hurricane Ian caused record storm surge and killed 152 people when it struck Florida’s Gulf coast. The Category 5 storm was the third-costliest weather disaster on record, and the deadliest hurricane to make landfall in Florida in nearly 90 years.

Scientists widely agree that climate change is affecting the frequency and magnitude of catastrophic storms like Ian, as both oceanic and atmospheric temperatures have climbed over the last 50 years. Yet despite these more intense storms, heat has proven to be deadlier.

Hurricane Ian was considered the deadliest single weather event of 2022, even though heat in Maricopa County killed more people by the end of the year.

And this has happened every year since 2013.

“We don’t talk of heat as a natural disaster,” said Pope Mosely, an intensive care physician and researcher at Arizona State University. “These heat waves, they are natural disasters, and the impact on humans is massive.”

Following Hurricane Ian, the Federal Emergency Management Agency has provided at least $5.5 billion in federal funds. But despite the significant loss of life in Maricopa County, the county does not receive any federal aid to prepare for heat or deal with its effects because FEMA does not classify heat as a major disaster.

Local and state leaders are moving to shift the tides. U.S. Rep. Ruben Gallego, D-Ariz., recently introduced the Extreme Heat Emergency Act of 2023, which would add extreme heat events to the FEMA list of major disasters.

By including extreme heat in the definition of a major disaster, FEMA would have the authority to provide federal resources and support to local governments in times of crisis caused by extreme heat.

Currently, FEMA's definition of major disasters includes everything from tidal waves to fires and explosions, yet omits the deadliest natural occurring phenomenon in the country.

Phoenix Mayor Kate Gallego also called on FEMA to revise its list of declared national disasters to include heat.

“Support from other levels of government would multiply our impact, which is why I’ve called for extreme heat to be added to FEMA’s declared disasters list,” she said. “This move would unlock additional resources to save lives.”

July 2023 was Phoenix’s hottest-ever month on record, with an average high of 114.7 degrees Fahrenheit (roughly 8 degrees warmer than Phoenix’s average July temperatures). The 31 straight days over 110 degrees surpassed the 18-day record set in 1974.

“While heat isn’t unfamiliar to us in Phoenix, climate change is resulting in more intense, prolonged heat events,” said Gallego.

Gallego said the city is expanding indoor shelter solutions, providing cooling centers across the city, and working with community-based organizations and volunteers to distribute thousands of heat relief kits.

Experts say one reason heat may not be considered a major disaster is because it is a “silent killer.” Deaths can sometimes take months to count and accumulate, compared to catastrophic storms like Ian where deaths can be quantified almost immediately and physical damage is conspicuous.

The effects of extreme temperatures go beyond threats to public health, reaching into the economy in ways that may not be as apparent as a flooded home from storm surge or a burned building from wildfire. Recent studies suggest extreme heat could cost the United States $100 billion annually from productivity loss alone.

Prolonged heat waves are also a major threat to Arizona’s $23.3 billion agriculture economy, according to the U.S. Department of Agriculture. Researchers have found that extreme temperatures reduce labor productivity, damage crops, and disrupt global trade.

Heat as a public health crisis: In low-income Phoenix neighborhoods, the lack of shade trees is a question of equity

Heat deaths in Maricopa outpace deaths from other major disasters, but the shift happened recently

In the 1990s, heat deaths in Maricopa County were reported at significantly lower numbers than they are today. In 1992, there were only three heat deaths reported by the county's health department. This is partly due to a change in how deaths are counted, although experts say climate variables and social risks have also contributed to the spike in deaths in the last decade.

Throughout the 90s, other natural disasters in the U.S., like Hurricane Andrew or the North American blizzard of 1996, would kill more people than heat in metro Phoenix, at least in the record books.

This would continue throughout the next decade, except for two years when heat would kill more people over a year than the deadliest single weather events. In 2002, tornadoes ripped through 17 midwestern and eastern states on the Veterans Day weekend, killing 36 people. Heat killed 38 people in the county that year.

And in 2009 a major ice storm across multiple states claimed the lives of 65 people, while in Maricopa County, 74 people were reported dead from heat by year's end.

The last year that Maricopa County’s annual heat death total fell below the deadliest natural disaster of the same year in the U.S. was 2012.

In the last nine years, heat has killed more people than Hurricane Harvey, Hurricane Ida, and the Camp Fire in California, to name a few, though the property damage and loss of life from each of those events was catastrophic. And in the last few years, the gap between heat deaths and other disasters has widened. In 2022, heat killed 273 more people than Hurricane Ian.

(The numbers include all 50 states states and DC, but not territories like Puerto Rico, where Hurricane Maria killed 2,975 people in 2017.)

But other extreme weather events are not causing the same upward curve in deaths.

According to a report by the World Metrological Organization, while natural disasters are becoming more frequent due to climate change, fewer people are dying because of early warning and disaster management. While the number of disasters over the last 50 years has increased fivefold, the number of deaths has fallen by two-thirds.

This does not include heat. Extreme heat is killing more people than it did in previous decades and, according to the Centers for Disease Control, average annual heat-related deaths are up 95% in the U.S. since 2010. That's part of the reason local leaders are urging federal attention.

They say FEMA assistance could allow for better warning and preparation, which could reduce the county’s death toll, and for heat to follow the curve with other natural disasters.

Rising temperatures: Phoenix is not prepared for a simultaneous heat wave and blackout, new research shows

How to better count — and account for — the growing number of people dying of heat-related causes

From 2013 to 2022, there was a 459% increase in heat deaths in Maricopa County. There is likely more than one reason why deaths have increased so steadily since 2000.

More than 1.5 million more people now call Maricopa County home than they did at the start of the new millennium. The larger population is putting more people in the path of dangerous temperatures.

Phoenix, like many cities across the county, has also seen a growing homeless population since the beginning of the pandemic. Around half of the heat deaths recorded last year were people experiencing homelessness.

Latest counts estimate roughly 6,000 people are living on the streets in Phoenix.

Experts say accurately tracking heat deaths can be a massive challenge, and in many parts of the country heat deaths are likely undercounted as heat-associated deaths are typically left out of the tally.

But in recent years Maricopa County has added heat-associated deaths to its official count.

Heat-associated deaths include those where heat was a secondary, yet still a major factor, such as a heart attack or complications from respiratory illnesses.

This is, in part, why the county’s official death count is higher today than it was in the 90's.

Even with this more comprehensive count, deaths caused directly by heat have also increased because of factors like an increased homeless population, longer stretches of heat waves and higher temperatures overnight.

Greg Hess, the Pima County Medical examiner, said there is a higher volume of deaths, ranging from heart attacks to strokes, during hotter months, and some of those can likely be linked to heat upon investigation. Hospitalizations from heart disease, sepsis, and other blood infections also increase during heatwaves, according to ASU. Pima County also began adding heat-associated deaths to its total this year.

“We get a lot more unhoused deceased people, or people outside with no air conditioning, who are dead because of drugs or natural disease in July than we do in December. And that’s clearly because it’s hot outside,” he said. “But it’s not as easy to wrap your mind around, like an easy-to-diagnose injury.”

Heat amplifies underlying diseases, like heart or cardiovascular conditions. The risk for fatal heart attacks may double during heat waves, according to a new study by the American Heart Association.

“If somebody shoots themselves in the head, they died from a gunshot wound, and that’s pretty easy to get a grip on what killed a person,” said Hess. “When you talk about heat, it’s a lot more subtle.”

Counting what is known as excess deaths is not a new method and has been used for decades to estimate death tolls for other natural disasters.

For example, if a person drowns from flooding during a hurricane, the official cause of death is listed as drowning. But because the storm is what contributed to the flooding and death, it is added to the entire death toll of that event.

This more accurate count can give federal officials a better understanding of the destruction caused by a weather event, which allows for appropriate funding, disaster declaration, and management.

Housing and heat: More homes mean more heat. Can new building codes help save metro Phoenix from disaster?

Heat islands, heat waves, and nighttime heat

While Phoenix has always been hot, Arizona State University's climate office says there has been a significant change in temperatures starting in the 1970s. It is projected that Phoenix may experience over 100 days per year over 105 degrees by 2040. By contrast, from 1951-2000 Phoenix experienced only about 44 days over 105 degrees.

Globally, the last eight years have been the warmest on record, but this summer is cooking up to be the hottest ever, both in Phoenix and across the world.

“With heat events, it’s not necessarily how hot it gets, but how long it stays hot,” said Mosely.

Phoenix tied another record last month, when nighttime lows did not dip below 90 degrees for seven days straight, including one night when the temperature never dropped below 97 degrees. That means when the air would naturally cool off as the sun is tucked away, the city saw no relief, only adding to the extreme heat wave.

Mosely attributes this, in part, to the urban heat island effect. Heat is exacerbated in urban areas as buildings, roads and other infrastructure absorb the sun’s heat and release it at night, when temperatures would typically begin to cool.

An ASU study found that nighttime temperatures in downtown Phoenix can be 10 to 15 degrees higher compared to nearby rural areas. During a long heat wave in 1974, the overnight averages were about 10 degrees lower than 2023.

“If you talk to people who have lived in Phoenix, for 20 or 25 years, they’ll tell you it used to cool off at night, but it doesn’t cool off anymore,” said Mosely. “But we can change that, by changing material, green space, and shading.”

And while a FEMA disaster declaration could help provide more resources for the county, experts say there are other ways the city can mitigate extreme temperatures by investing in long-term resiliency planning to address the heat island.

Heat island reduction strategies, such as green or cool roofs, cool pavements, or increased vegetation and trees, can all lower urban temperatures.

Cool pavements — which absorb less solar energy, and in the case of permeable pavements, evaporate more water, than traditional materials — can be used for roads and parking lots to help cool urban areas.

Installing cool or green roofs and planting trees and vegetation can help keep buildings and their surroundings cooler. These measures also reduce electricity demand, which helps improve the reliability of the electric system, particularly during heat waves.

“Phoenix is the most important climate laboratory that exists,” said Mosely. “The solutions that Phoenix finds are going to be really important for a lot of people all over the world.”

The city has acted in recent years in attempts to minimize the impacts of climate change on public health with plans to reduce its carbon footprint and expand green space.

The city says it is working to revise its tree and shade master plan, which was originally drafted in 2010. The original master plan set a goal of an average 25 percent tree canopy coverage by 2030. According to the American Forest’s tree equity score, which maps canopy cover across the U.S., Phoenix is significantly below its goal set 13 years ago, with an average of 10 percent canopy cover across the city.

Phoenix is also taking steps like electrifying city buses. Earlier this year city council voted to buy 40 electric and hybrid buses per year over the next five years to reduce the city’s carbon footprint.

The city’s 2021 Climate Action Plan also includes goals for electric vehicle adoption and charging equipment that could help slow carbon emissions from tailpipes. The city is projecting 50 percent of all vehicle sales in the city will be electric by 2030.

But Phoenix’s EV roadmap acknowledges that the city currently does not have the number of EV chargers, nor the supporting infrastructure, to support target numbers of EVs for the public, the city’s fleet or workplace users.

“Phoenix is ground zero for the solutions that will need to be applied all over the place as temperatures rise,” said Mosely. “And we have an opportunity to do things to solve a lot of the problems because we need to.”

As summer rolls on, officials say more deaths will likely be added to the official death count. That adds urgency, officials say, for FEMA to declare heat as a major disaster to help save lives and change course on the trend of Maricopa County leading the nation in weather-caused deaths.

Jake Frederico covers environment issues for The Arizona Republic and azcentral. Send tips or questions to jake.frederico@arizonarepublic.com.

Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Sign up for AZ Climate, our environment newsletter and follow The Republic's environmental reporting team at environment.azcentral.com and @azcenvironment on Facebook, X and Instagram.

You can support environmental journalism in Arizona by subscribing to azcentral today.

This article originally appeared on Arizona Republic: Arizona officials say heat should be classified as a natural disaster