Maricopa County health officials reported Wednesday that heat-related deaths continue to rise, reaching their highest number since 2006 when record keeping began.

According to the 2021 Maricopa County Department of Public Health heat-associated death report, 339 were recorded in 2021, the highest number since 2006.

"This tragic number of deaths shows us that heat continues to be a major issue affecting the health of Maricopa County residents,” Dr. Nick Staab, medical epidemiologist at MCDPH, said.

“Looking deeper at the numbers, we see that anyone can be at risk of serious illness and death from heat, and everyone needs to take precautions during the entire heat season.” 

Three-quarters of the deaths occurred outdoors and 130 of those where among the homeless. Of those deaths that occurred indoors, 86% had an air conditioner in their home but in 75% of those cases the unit was not working.

In 19% percent of the cases air conditioners were not turned on, 3% did not have working electricity, the report stated.

Other  points in the report:

• Most heat-associated deaths occurred in the months of June, July and August, but heat-associated deaths can occur as early as April and as late as November. 
• Three out of four heat-associated deaths occurred on days that did not have an excessive-heat warning. 
• 86% of heat-associated deaths were residents of Maricopa County, and two-thirds of those had lived in the county for more than 20 years.

“These data tell us that it’s not just visitors or newer residents who can be severely affected by our hot weather,” Staab said. “Even when we think we’ve gotten used to Arizona summers, we need to take precautions like staying hydrated and avoiding outdoor activity in the hottest part of the day.”

A county release stated it is also important to regularly check on family, friends and neighbors, especially those with chronic medical conditions, to prevent heat-related tragedies.

Water distribution and emergency cooling centers have been established throughout the county for those who do not have access to cool, indoor environments.  A map showing all the cooling centers can be found at HeatAZ.org.

A person is included in MCDPH’s heat-associated death data only after the Maricopa County Medical Examiner confirms that heat has caused or contributed to the cause of death.