MARY LOUISE KELLY, HOST:
Phoenix, where daytime temperatures have climbed as high as 119 degrees this summer, has set a new heat record for temps at night. This summer the city's had more nights than ever where the low temperature - the low - is 90 degrees or higher. KJZZ's Katherine Davis-Young reports.
KATHERINE DAVIS-YOUNG, BYLINE: Randy Cerveny researches geographical sciences at Arizona State University. He says when he looks at the scorching temperatures recorded in Phoenix this summer, there's one trend he finds most troubling.
RANDY CERVENY: Having more record minimums than we are record maximums.
DAVIS-YOUNG: While Phoenix's daytime highs have climbed gradually over the last couple decades, Cerveny says overnight lows have shot up exponentially.
CERVENY: Back before 2000, we would have basically five or less days in which the temperature didn't go below 90.
DAVIS-YOUNG: Thirty-seven nights this summer have already been that hot. The urban heat island effect is partly to blame. As Phoenix's population has boomed, the metro area has been paved over with more and more heat-trapping concrete. But Cerveny thinks the spike in the number of 90-degree nights over the last few years has more to do with greenhouse gas emissions.
CERVENY: Carbon dioxide traps in the heat that's collected during the day, and therefore, we get hotter during the night. So it's one of the clear indications that we have that climate change is going on.
DAVIS-YOUNG: And round-the-clock heat creates serious health risks, especially for unsheltered people, says Dr. Nick Staab, assistant medical director for Maricopa County Public Health.
NICK STAAB: It just doesn't give the body enough time to recover from those really high temperatures that we're experiencing during the day.
DAVIS-YOUNG: Staab's department analyzed five years worth of local hospital records and found 150% more heat-related illnesses reported when low temperatures were in the 90s compared to days with lows in the 80s. Phoenix for years has used libraries and public buildings as cooling centers in hot months to give vulnerable people places to get out of the heat. But before this summer, those sites were only open during the day. In May, for the first time, the city started offering overnight heat relief at two cooling centers and keeping three others open until 10 P.M.
On a recent evening at one of the overnight sites near downtown Phoenix, there was already a crowd of people waiting to get in before doors even opened. Among those in line was Adeline Gotia (ph). She's 71 and recovering from a stroke. She was supposed to move cross-country recently, but the people who were going to help her couldn't make it to Phoenix.
ADELINE GOTIA: I got stranded here.
DAVIS-YOUNG: So she's been spending nights at the heat relief site.
GOTIA: Because I came to them and asked, what can I do?
DAVIS-YOUNG: There are no beds inside, but guests can nap in chairs. And with homeless shelters across the metro area at capacity, demand for those seats has been enormous. The city reports its five extended-hour heat relief sites have had more than 20,000 visits. The goal of the overnight sites was to reduce heat-related deaths, which have soared in the last decade. So far this year, the county has confirmed more than a hundred heat-related deaths and is investigating more than 400 others. That is a slight decrease compared to last year, but it's still likely to be one of the deadliest summers on record, and future summers could be even hotter.
Meanwhile, people are becoming homeless in Maricopa County at about twice the rate homeless people are finding housing. For now, Gotia is grateful at least to have had an option for getting inside since losing her home. I asked what would have happened to her if this site hadn't been open for overnight heat relief lately.
GOTIA: I hate to think of it, to be honest.
DAVIS-YOUNG: For NPR News, I'm Katherine Davis-Young in Phoenix.
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