Impacts of climate change and extreme weather warnings on ischemic heart disease mortality in the United States

To support adaptation strategies that reduce health risks from extreme climate exposure, it is essential to better understand the health impacts of temperature and evaluate the effectiveness of existing early warning systems. This study estimates the threshold effects of temperature and extreme weather warnings on ischemic heart disease (IHD) mortality, using U.S. panel data from 2015 to 2022. A panel threshold model was first applied to determine if temperature thresholds exist in the temperature-IHD mortality relationship, and Poisson Quasi-MLE was used to estimate the impacts of temperature and extreme weather warnings on IHD mortality across various temperature ranges. We found single temperature thresholds ranging from 16.4 °C (lag 1–4) to 17.6 °C (lag 0). Colder temperatures contribute to higher IHD mortality rates, with temperature decrease having a more adverse impact in warmer weather. Nationwide, increased IHD mortality is also associated with higher influenza prevalence, adverse COVID-19 hospitalizations, and increased air pressure in warm weather, as well as elevated ${PM}_{2.5}$ exposure in cold weather. The effectiveness of extreme weather warnings varies across temperature ranges and climate regions. Wind chill warnings (WCW) issuance is associated with an estimated 2–3 fewer IHD deaths per state per week nationwide and about 3–4 fewer IHD deaths per week in the Northwest and Southwest regions. Excessive heat warnings (EHW) had no protective impact nationwide but reduced mortality in the West. The study provides new insights into how climate factors and extreme weather warnings affect IHD mortality across temperature ranges, proposing enhanced proactive measures to adapt to climate change.