Medical examiners in Arizona have implemented new protocols to track heat-related deaths. Dr. Greg Hess, the medical examiner for Pima County, and Dr. Jeff Johnston, the lead forensic pathologist for Maricopa County, are now documenting environmental heat exposure as a contributing factor in deaths that were previously attributed primarily to other causes. This change aims to provide more comprehensive data on the impact of extreme heat on public health.
The effort follows years of observed discrepancies between official death tolls and statistical estimates. While the Centers for Disease Control and Prevention (CDC) estimates approximately 1,200 annual heat-related deaths nationally, a 2020 study from Boston University suggests the actual figure may be at least 10,000. Historically, heat is rarely listed on death certificates unless it is the primary cause, such as heatstroke, often omitting cases where heat exacerbated existing conditions like heart disease, diabetes, or substance use.
In Maricopa County, which includes Phoenix, Dr. Johnston began requiring death investigators to collect contextual evidence at death scenes between April and October. Investigators now record room temperatures, check for functioning air conditioning, and note if victims were struggling to pay electric bills. Since changing the counting technique, reported heat deaths in Maricopa rose from a high of 182 in the mid-2010s to 645 in 2023. Pima County hired an epidemiologist, Tasha Tully, to create a near-real-time dashboard to share death data with city and state offices.
The scale of the issue is significant for residents in the Southwest. In 2023, Phoenix experienced a 31-day streak of temperatures at or above 110 degrees Fahrenheit. During the 2023 heat wave, the Maricopa County medical examiner’s office handled twice the usual number of bodies, with staff performing 80 scene investigations per week. For families, the classification of a death as disaster-related can be a factor in receiving federal assistance; the Federal Emergency Management Agency (FEMA) provides funds for funeral costs only if the death is associated with a federally declared disaster and listed as such on the death certificate.
However, heat is not currently classified as a "natural disaster" eligible for federal aid, and there is no nationally consistent method for reporting disaster-related deaths. While the National Association of Medical Examiners recommended new standards in 2022, adoption remains voluntary. In Arizona, the Pima County medical examiner's office reported 120 heat-related deaths in July 2023. Medical examiners continue to provide this data to policymakers to inform heat-mitigation strategies.