PHOENIX (3TV/CBS 5) — A new study done by researchers, including David Hondula, the city of Phoenix’s director of Heat Response and Mitigation, shows how bad it could be if the electrical grid failed. The study looked at what would happen if a citywide blackout occurred during a heat wave lasting for five days. There would be two days with a total blackout, then power gradually restored over the next three days. The study found emergency operations in Phoenix would become overwhelmed.

Arizona’s heat is no joke; many rely on our air conditioning to get us through it. But, according to the New York Times, a new study shows if there is a blackout during a heat wave in Phoenix, more than 12,000 people would die and close to 800,000 people would need emergency care for heat-related illnesses. This would overwhelm the hospital system in Phoenix, which they say only has 3,000 ER beds.

“Here in Phoenix, we know heat to be a significant concern. Something we deal with probably more on the extreme side than perhaps some other cities in the nation do,” said Brian Lee. He is the director of emergency management for the city of Phoenix. They are responsible for coordinating resources and people while working with other cities if an emergency were to occur.

While he says this study is a worst-case scenario, there are periods often during the monsoon where areas lose power. “For us it’s getting a quick assessment to find out what the extent and scope and scale of that particular outage looks like,” Lee said. “The heat is extreme and does take a toll on a person.” He says working closely with power companies is crucial. “There are systems they have in place to be able to prevent blackouts from happening in the first place,” Lee said.

Now there are some limitations in the study. It assumed people would stay put during a heat wave and blackout. While in reality, some would try to evacuate and go to cooling centers.

Phoenix Mayor Kate Gallego is calling on FEMA to add extreme heat to the list of disasters like floods and hurricanes that could prompt a federal disaster declaration. But, Lee says, as we enter a hot summer, make sure you have a plan. “If it’s in response to heat related incident, understand where you can go and what can you do in your own home,” he said.

The study also shows if the city planted enough trees to shade half of its streets, deaths would drop by 27 percent in Phoenix. And if installed highly reflective “cool roofs” on every building, deaths would drop by 66 percent in Phoenix.

We contacted the Arizona Corporation Commission to ask their thoughts on this study. In a statement, they said:

SRP also told Arizona’s Family they could not comment on the study’s specifics but invest in our regional grid to mitigate the risk of a prolonged outage from happening. In a statement, they said:

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