After reviewing data from millions of adults between May-September of 2008-2017, researchers found that each additional day of extreme summer heat was linked to an additional .07 death for every 100,000 adults. In other words, an increase in hot summer days, where it felt at least 90 degrees, was associated with an average of 1,373 extra deaths each year. This ranged from an additional 752 deaths in 2008 to 2,337 in 2011. The research published in JAMA Network Open and was partially supported by NHLBI.
Through a separate analysis in Circulation about cardiovascular-related deaths linked to extreme heat, the authors shared that hotter temperatures can put extra pressure on the heart. This can lead to a faster heart rate and an increase in inflammatory markers related to severe blood clotting. In both general and cardiovascular-specific reviews, the authors found that older adults, men, and Black adults were more likely to be affected by extreme heat.
The authors note an increase in hot days may exacerbate heat-related health disparities and shared the role that studying community-focused solutions, such as increasing access to shade or cooling centers, may have in potentially offsetting these risks.