Why Are So Many People Dying From The Heat? Researchers Have Some Ideas

By Scott Bourque
Published: Friday, September 13, 2019 - 4:53pm

Forty-seven people have died from heat-related conditions in Maricopa County this year, a 29% increase in confirmed heat deaths over last year. One hundred forty-six cases are still under investigation.

This marks a record for heat-related deaths, and researchers are trying to identify why this year has seen such a sharp spike, despite a cool spring and average summer.

“Just the raw temperatures don’t necessarily correlate with heat deaths,” said Liza Kurtz, a Ph.D. candidate at Arizona State University who studies heat deaths and disaster sociology. “It’s really hard to say ‘what is the single factor driving this year’s increase?’”

Kurtz and her team are investigating several hypotheses, including statistical bias, and social problems being exacerbated by extreme heat.

“Heat touches everything we do,” Kurtz said. “It’s really hard to say, ‘what is the single factor driving this increase?’”

Hopeful Hypothesis

The increase in heat deaths could be attributed to how the medical examiner’s office classifies the cause of death during autopsies. This could be caused by a number of factors.

“If there are fewer deaths that require investigation by the medical examiner overall, it opens the door for faster understanding of the cause of death,” Kurtz said. “We might be seeing an increase in heat (as the) cause of death because they’re able to produce them faster than this time last year, because the overall number of deaths has gone down.”

If the data supported this hypothesis, Kurtz said it would actually be a positive revelation, because it would mean the medical examiner has gotten faster at identifying heat deaths.

“It would really be overall a net gain,” she said. “We’ll be able to identify heat deaths more quickly than we have in the previous years.”

Research continues on this idea, but definitive answers won’t be available until data becomes available at the end of the year.

“That would be great if that’s the case,” Kurtz said. “We’ll certainly know later in the year once we do the final tally, we’ll be able to see if the raw numbers of people who passed away from heat are higher than last year. Right now we don’t know.”

Downstream Effects

In 2016, the Maricopa County Justice Courts processed more than 22,000 evictions, and Phoenix is in the midst of an affordable housing crisis.

“It’s certainly a possibility that more folks are on the streets, and therefore might be exposed to heat,” Kurtz said. Arizona’s homeless population grew 10% in 2018. In addition to homeless exposure, many people have returned to working outside during the day, instead of in the early mornings.

“People don’t heat as seriously after the month of, say, June and July,” Kurtz said. “Maybe more people are exposed because outdoor workers go back to work in August.”

Drug addiction is another potential factor. Researchers will be analyzing statistics on drug use, since

“If we see a spike in drug users who are exposed to heat, then we might see a spike in deaths too,” Kurtz said. “There’s all these downstream effects.”

More Stories From KJZZ