This summer has been the deadliest on record for heat-related deaths in Arizona’s largest county, with public health statistics this week confirming 359 such deaths just days before the end of the heat season six months.
The jump comes amid a growing homelessness crisis in the region and raises questions about how to better protect vulnerable people in the desert southwest as temperatures soar.
Climate change has fueled more intense, frequent and long-lasting heat waves that can regularly reach triple digits.
According to the National Weather Service, the highest temperature recorded this year at Phoenix Sky Harbor International Airport was 115F (46.1C) on July 11, with mercury reaching 114F (45.5C) on June 11 and the 16 and July 22.
Heat-related deaths in Maricopa County this year exceeded 339 confirmed deaths in 2021 and the final number could be even higher, with another 91 deaths still under investigation.
The county has more than a decade of experience tracking heat-related deaths, but comparable numbers are hard to find in other regions such as the Pacific Northwest, which has only seen intense heat waves in recent years.
In California, researchers found that unhoused people, especially those with mental illness, were much more likely to end up in hospital during extreme heat than housed people, based on a study of emergency room admissions.
Nearly 80% of heat-related deaths in Maricopa County this year have occurred outdoors, but preliminary heat reports for this year do not estimate the number of homeless deaths rather than among people who worked away or were away for other reasons.
But the increase comes at a time when hundreds of people are sleeping in tents around downtown Phoenix amid soaring rents and evictions.
“With so many homeless, it makes sense that more people are dying in the heat,” said Amy Schwabenlender, executive director of the Human Services Campus in downtown Phoenix, which brings together homeless-serving agencies. .
She said around 900 people are currently staying in shelters on campus, with around 1,000 more in tents on the streets outside the fenced property. A year ago, about 300 people were sleeping just outside campus.
Information on the role that substance use played in this year’s heat-related deaths is not yet available.
But last year, substance use was a factor in 60% of those deaths in Maricopa County. Methamphetamine was found in 91% of drug-related deaths and fentanyl, an opioid, in 30%. While fentanyl is more likely to result in an overdose, methamphetamine can create changes in the body that make a user more vulnerable to heat, increasing blood pressure, heart rate, and breathing. Homeless people accounted for 38% of drug-related deaths in 2021.
Men, African Americans, Native Americans and people ages 75 and older had the highest rates of heat-related deaths in the county in 2021.
David Hondula, one-year-old director of the City of Phoenix’s Office of Heat Response and Mitigation, said in a report to city council last week that his team is studying the numbers to understand what’s behind the rise in deaths and how to predict next summer.
Hondula said heat-related calls for help to the Phoenix Fire Department over the summer are expected to end at least 10 to 20 percent above 2021.