One deadly summer: Maricopa County releases final 2021 heat death report

One year later, the Maricopa County Dept. of Public Health has released their final heat death report for 2021 - and it broke records.

Health officials said 339 people died from heat-related issues in the county last year. This marks the highest number of heat deaths since Maricopa County started recording the data back in 2006.

People are only added to the data after the county medical examiner confirms that heat caused or contributed to their death. Normally, potential heat-related cases are listed as "under investigation." 

Here's some key points noted in the report:


  • Of those who died, 130 of them were homeless
  • Maricopa County residents consisted of 88% of the deaths, and ⅔ of that number had been living in the county for more than 20 years


  • 75% of heat-associated deaths happened outside
  • For those who died indoors, 88% had an air conditioner. The A/C was not working in 75% of those cases.


  • Most heat-related deaths happened in June, July and August, but some occurred as early as April and as late as November
  • ⅔ of deaths happened on days without an Excessive Heat Warning

"These data tell us that it’s not just visitors or newer residents who can be severely affected by our hot weather," said Nick Staab, a medical epidemiologist with the Maricopa County Dept. of Public Health in a statement. "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."

Continued coverage

Preventing heat exhaustion/heat stroke

What are Heat Emergencies?

Heat Cramps: Profuse sweating, fatigue, extreme thirst, muscle cramps

Heat Exhaustion: Headache, dizziness, weakness, nausea/vomit, Cool/moist skin

Heat Stroke: Elevated temp. +103degrees, confusion/irrational behavior, dry/hot skin, rapid shallow breathing, rapid weak pulse (shock), seizures, unconscious

What to do

  • Get person into shade or cool location
  • Cool person with cool, wet cloths (neck, groin, armpits, head) and fan body
  • Sip cool water if person is alert
  • For muscle cramps, massage muscles gently, but firmly until relaxed
  • *If symptoms worsen, call 911

What not to do

  • Do not give anything by mouth if person is vomiting, unable to swallow or unconscious
  • Do not underestimate the seriousness of a heat emergency
  • Prevention/Preparation for hike/exercise in heat

Know your limitations

  • Hydrate (begins day prior to hike/exercise, hour before hike, during and after)
  • Wear proper clothing, lightweight and light color, protect head, proper shoes
  • Always carry a cell phone and best to hike with company
  • Always tell someone where you are hiking and when to plan to return

The Arizona Department of Health Services stated the following precautions can be taken to prevent heat exhaustion or heat stroke:

  • Stay in air-conditioned buildings
  • Find a cooling center/hydration station
  • Limit outdoor activity during the hottest part of the day (mid-day)
  • Check on at-risk friends, family, and neighbors at least twice a day
  • Drink water before, during, and after working or exercising outside
  • Check the UV Index
  • Check the heat risk map