Two new studies led by Penn LDI senior fellow and Perelman School of Medicine cardiologist Sameed Khatana are bringing a greater focus on the increasing health threat of extreme heat waves and the deadly connection between those weather events and cardiovascular mortality.

The two studies—published in JAMA Network Open and in the journal Circulation—are co-authored by LDI executive director Rachel M. Werner, and LDI director of research Peter Groeneveld.

The first analysis intersects periods of extreme heat with records of adult deaths from all causes across the country’s 3,108 contiguous counties from 2008 to 2017. Previous research on extreme heat and mortality had focused on a limited number of urban areas. In this new work, the researchers found higher levels of all-cause mortality in those extreme heat periods with a greater increase in deaths among older adults, males, and Blacks.

The second study intersects periods of extreme heat in all counties with records of monthly cardiovascular deaths from 2008 to 2017. Researchers found extreme heat associated with an estimated 5,958 additional cardiovascular disease deaths in the counties during the period. The increase in deaths is greater among males compared to females, and greater for Black population compared to white populations.

Both studies make the point that the extreme heat death rate disparities between white people and Black people is likely to widen as the overall national incidence of both cardiovascular disease as well as climate-change-driven extreme heat continues to increase over the coming decades.

“The health impacts of extreme heat are underappreciated by government agencies as well as health care providers,” says Khatana. “Although there has been a growing realization that extreme heat can be detrimental to the health of individuals, many local governments still have no heat plans; and access to cooling centers, particularly for vulnerable individuals, is often lacking. Many areas, such as the Northeast, that in the past have not had much extreme heat are now experiencing these events with increasing frequency. Therefore, creating plans for how to get access to cooling for vulnerable individuals during extreme heat events is crucial.”