The hidden death toll from extreme heat

**SPEAKER_1** (0:00)
Support for Here & Now Anytime comes from MathWorks, creator of MATLAB and Simulink software, to design and develop engineered systems, accelerating the pace of discovery in engineering and science. Learn more at mathworks.com.

**Carol Rosenberg** (0:16)
WBUR Podcast, Boston.

**Quinn Adams** (0:21)
You know, if we think that a thousand people die each year due to heat, it doesn't sound like that big of a problem compared to if we have, you know, over 10,000 people dying each year of extreme heat, that starts to sound like a really big problem.

**Chris Bentley** (0:36)
Heat is killing way more people than official statistics show.
It's Monday, August 31st, and this is Here & Now Anytime from NPR and WBUR. I'm Chris Bentley. Today on the show, when will it be safe to visit the Grand Canyon again after deadly flash flooding over the weekend? Also almost 25 years after September 11th, 2001, the man accused of organizing the terrorist attacks finally has a trial date. One man whose brother died on 9-11 says a weaning justice has been like psychological torture, and he's glad the death penalty is on the table.

**Don Arias** (1:26)
Now, this thing's gone on for 25 years. If these guys die of old age at Gitmo, I'm fine with that too.

**Chris Bentley** (1:34)
What's going on in the case of Khalid Shaikh Mohammed coming up in about 10 minutes?
But first, heat plays a role in thousands of American deaths every year. But official statistics are not counting them. That's one finding of a new investigation from NPR and Boston University that took years and produced a paper soon to be published in a scientific journal. Quinn Adams is a lead partner in the investigation. She's with BU's Center for Climate and Health, and she told Peter O'Dowd, heat-related deaths are chronically undercounted.

**Quinn Adams** (2:14)
People who record these deaths, either doctors or coroners, tend to record the death based on what they see right in front of them. So somebody might die because of a heart attack or an underlying heart condition, when in reality they died sooner because of an extreme heat event. But those deaths aren't being recorded as heat-related. So we're missing a lot of these deaths and people who have preexisting conditions that were then made worse or exacerbated by a heat event.

**Peter O'Dowd** (2:44)
Missing quite a few. The investigation found that between 2018 and 2025, heat-related deaths are five times higher than what's been estimated. And I was just looking at one graph, a chart that says in 2022, the CDC reported just over 1700 deaths. The model suggests the real number is close to 11,000. So it sounds like the story is similar year after year.

**Quinn Adams** (3:11)
That's right. Yeah. And what we're doing in our analysis is looking at more of a statistical measure of, you know, when heat goes up, what happens to mortality across the country. And that's why we're able to capture more deaths than are recorded in these official counts.

**Peter O'Dowd** (3:27)
Is this true for the entire country or just in hot places?

**Quinn Adams** (3:31)
It's true pretty much across the board. However, we do see a pretty interesting result actually coming out of places like Maricopa County, which is where Phoenix, Arizona is. We see that they actually have official counts that are higher than our modeled estimates. And the reason for that is because they've done a lot of really significant work in understanding how to record heat related mortality and really how to understand which deaths are heat related.

**Peter O'Dowd** (3:59)
Well, as someone who is in Maricopa County right now, I can tell you that there has been a real urgency to figure out the statistics and the numbers and the real picture here because a record number of people have been dying because of heat in recent years. So what has happened in Maricopa County and Arizona? That might be a model for the rest of the country.

**Quinn Adams** (4:18)
Yeah, well, first of all, they have appointed a Chief Heat Officer, David Hondula, who has done amazing work in really not only identifying the health impacts of heat, but applying interventions across the board.

**Peter O'Dowd** (4:33)
At the City of Phoenix, right.

**Quinn Adams** (4:34)
That's correct. So he's been implementing what's called this Heat Relief Network. So it allows businesses in the area and cooling centers to open during periods of extreme heat, not only allowing for the city to really recognize the true impact of heat and the burden in Phoenix, but also to provide interventions that allow people to escape from the heat.

**Peter O'Dowd** (4:58)
Have we seen this get more complicated and more difficult to track as climate change continues to make heat waves longer and more intense?