Half of Phoenix, Arizona, would end up in the ER if the city has a blackout during a heat wave, study finds

• Half of Phoenix, Arizona, would go to the ER if there's a blackout during a heatwave, a new study says.
• 800,000 people would require emergency care for heat-related illnesses, and 13,000 would die.

Half of the population of Phoenix, Arizona, would end up in the emergency room if the city had a blackout during a heat wave, according to a shocking new study.

The research, published today, estimated that around 800,000 residents would need emergency care for heat-related conditions like heat stroke.

That would overwhelm the city's 3,000 emergency department beds, the study said. And with Arizona's strained healthcare system, about 13,000 people would die, the study concluded.

Phoenix — similar to other cities included in the study that are dealing with extreme heat such as Atlanta and Detroit — is heavily reliant on air conditioning and other electric-powered cooling systems.

If a blackout left citizens without those systems, a heat wave would have dire consequences, the researchers found.

"I describe this as probably the greatest climate-related hazard we can imagine: a blackout during a heat wave," Brian Stone Jr., the lead author of the study and a professor in the School of City and Regional Planning at the Georgia Institute of Technology, told The New York Times.

The study involved modeling outdoor and indoor temperatures and daily activity patterns for residents, as well as looking back at historical heat wave events in Phoenix. Researchers also projected future heat waves as temperatures fluctuate based on climate models.

Heat-related deaths in Phoenix have skyrocketed over the past few years, reaching a peak of 425 in 2022, according to Maricopa County data.

The city saw record-breaking temperatures in April of this year, according to local weather reports.