The relentless impact of extreme heat on heart health is raising alarm bells as a recent report highlights the potential rise in heat-related cardiovascular fatalities due to climate change in the coming decades. Particularly vulnerable are Black adults, seniors, and individuals residing in urban areas.
Between 2008 and 2019, the heat index, a measure that factors in both temperature and humidity, soared to at least 90 degrees Fahrenheit on an average of 54 days during each summer in the US. These scorching days were linked to nearly 1,700 excess cardiovascular deaths annually, as revealed in a study published in the journal Circulation.
If global fossil-fuel development continues unabated, and the world only makes minimal efforts to curb planet-warming pollution, the US could face a staggering 80 days of extreme heat each summer. This scenario could result in a more than threefold increase in heat-related cardiovascular deaths, with an estimated 5,500 excess deaths annually, according to the research findings.
Even under a more optimistic scenario, one where planned and ongoing climate change mitigation measures are implemented, there could still be an increase to 71 days of extreme heat per year. This could lead to a 2.6-fold rise in heat-related heart mortality, with over 4,300 excess cardiovascular deaths attributed to extreme heat by the mid-century.
It’s crucial to note that heart disease remains the leading cause of death in the US, and extreme heat currently accounts for a relatively small share of total cardiovascular fatalities, roughly 1 in 500 cases. However, as hot days become increasingly frequent, proactive risk mitigation becomes imperative, emphasized Dr. Lawrence Fine, a senior adviser at the National Institutes of Health’s National Heart, Lung, and Blood Institute, which partially funded the study.
Dr. Fine pointed out, “The thing about heat-related deaths is that they’re concentrated when it’s very hot, and they’re also concentrated among individuals with preexisting health conditions or other vulnerabilities.” Heatwaves can strain emergency rooms and the broader healthcare system, posing a severe threat to specific demographic groups.
He added, “Addressing the root causes of rising temperatures and heart disease is essential, but it’s equally vital for people to recognize their vulnerability and have a specific plan for coping with extreme heat when exposed to it.”
The research findings are based on projections considering population growth, migration patterns in the US, and greenhouse gas emission trends as outlined in the United Nation’s Intergovernmental Panel on Climate Change report. These projections extend from 2036 to 2065 and are based on county-level data for the 48 contiguous states in the US.
The summer of 2023 exemplified the perilous consequences of extreme heat, with Maricopa County, Arizona, reporting an alarming 469 heat-associated fatalities, making it the deadliest year for heat deaths since tracking began in 2006. The Southwest experienced record-breaking temperatures, with Phoenix enduring 31 consecutive days at or above 110 degrees Fahrenheit from June to July.
Heat-related fatalities have surged in the US in recent years, with 2022 witnessing over 1,700 deaths attributed to heat-related causes. This figure more than doubled over the past five years. Experts caution that this data likely underestimates the true impact of extreme heat, as heat exposure is not always thoroughly documented.