14 new heat-associated deaths in Maricopa County; 39 deaths so far in 2023

As the historic heat wave in the Valley tempered and gave residents a bit of a rest, 14 more heat-associated deaths have been reported, according to the weekly Maricopa County Heat report released Wednesday morning. 

This is a two-fold increase compared to last week's report when only seven new deaths were reported by authorities. The 14 heat-associated deaths - defined as deaths both directly and indirectly caused by heat - confirmed by the county increased the number of heat deaths from 25 to 39 so far in 2023.

About 10 of the heat-associated deaths happened during the week of July 16, when temperatures in the Valley reached 119 twice.

At least 312 deaths are still under investigation by authorities. In the whole of 2022, 425 deaths were reported by authorities.

Of the deaths reported so far this year, 77% happened outdoors. But, different from the week prior, the people most affected by the heat are now people aged 65 to 74 years, making up 28% of deaths.

So far in 2023, 31% of deaths were people who were unhoused, compared to 2022 where 44% of deaths were unhoused persons. The heat wave also caused problems for local hospitals with about 2% of all hospital visits being related to the heat, the report outlined.

Of the 14 indoor deaths reported this week, nine happened indoors, with seven of them happening in places where A/C systems were broken or not in use. The rest of the indoor deaths did not have air conditioning present.

Temperatures are slated to hit 115 degrees later this week.

Injuries and death:Heat-related illnesses are on the rise in ongoing Arizona heat wave

Heat-related deaths set record in 2022

In 2022, a record 425 people died of heat-related causes — death indirectly caused by heat — in Maricopa County. A decade ago, the county reported just 75 heat deaths. Researchers have said the growing number of lives lost underlines an urgent need to scale up efforts to protect those who are most vulnerable. 

In Phoenix, the urban heat-island effect contributes to hotter temperatures. 

The vast areas of concrete and asphalt soak up heat from the sun during the day and radiate it at night, pushing temperatures higher than in other undeveloped areas. 

Stay safe:How to protect yourself from burns in Arizona's extreme heat

Since 2009, more than 2,000 people have died from exposure to excessive natural heat. Heat deaths of people experiencing homelessness more than doubled between 2019 and 2020, according to Maricopa County data.

July was the hottest month on record for a US city

The historic heat wave hitting the Valley set local and national records.

According to the National Weather Service in Phoenix, July wrapped up with an average temperature of 102.7 degrees Fahrenheit, beating the Phoenix area's previous record of 99.1 degrees, set back in August 2020. The record stands for as far back as records have been kept on Phoenix weather, which is 1895.

Last month set and broke heat record after heat record nearly every day since July 8. According to the weather service:

• The average maximum temperature in July was 114.7 degrees.
• The average minimum temperature was 90.8.
• Every day in July had above-normal temperatures.
• Only one day in July had a high temperature below 110 degrees.
• July set a new all-time record for the most consecutive days with high temperatures at or above 110 degrees (31 days) from June 30 to July 30.
• July had 19 days with low temperatures at 90 degrees or higher.
• 17 days in July hit maximum temperatures at or above 115 degrees, breaking the previous record of six days set in 2020.
• July set a new all-time record warm low temperature of 97 degrees.
• Three days in July reached 119 degrees.
• 12 days in July broke or tied daily high-temperature records.
• 16 days in July broke or tied daily warm low-temperature records.
• The longest stretch of days under an excessive heat warning was set from July 1 to July 29, nearly quadrupling the number of days from the previous record, which was eight days.

Hot weather tips

The Arizona Department of Health Services provided tips to prevent heat-related illness:

• Drink water: It is recommended to drink at least 2 liters of water per day if people are staying inside all day. Those who spend time outdoors should drink 1 to 2 liters per hour they are outside.
• Dress for the heat: Wear light-weight and light-colored clothing. Sunscreen should always be applied to exposed skin and it is recommended to wear a hat or use an umbrella when outdoors.
• Eat small meals and eat more often: It is recommended to avoid foods high in protein that increase metabolic heat
• Monitor those at risk: Check on friends, family or others for signs of heat exhaustion or heat stroke. 
• Slow down and avoid strenuous activity: It is recommended to only do strenuous activity during the coolest hours of the day, between 4 and 7 a.m.
• Stay indoors.
• Take breaks when engaged in physical activity: Take a break in a cool place when doing activity outside on a hot day.

Republic Reporter Laura Daniella Sepulveda contributed to this report.