Heat-Related Mortality and the Impact of Heat Health Warning Systems: Evidence From Three U.S. Cities

Excess heat-related mortality is of increasing public health concern worldwide, especially in urban areas and among the very young and the elderly. Heat waves are a leading cause of weather–related fatalities in the U.S. and around the world, resulting in hundreds of deaths annually and are projected to increase in frequency, magnitude and duration throughout the 21st century. The U.S. urban Northeast is particularly susceptible to the effects of heat due to the substantial heat island effect, as well as its large population, including many vulnerable individuals. Although numerous studies have focused on heat-related mortality in the region, many questions remain. For instance, long term trends in heat adaptation, as well as the effectiveness of heat warning systems, are yet to be well understood. To address these research gaps, we first establish historical temperature - mortality relationships for the three major Northeast cities: Boston, New York City and Philadelphia. Next, we analyze if these relationships have changed over the course of the last four decades, in particular after the implementation of heat warning systems in the three cities. The study will enhance our understanding of urban adaptation to extreme temperatures as well as the effectiveness of heat warnings in reducing heat-related mortality. The study findings can have important implications for future public health research and practice and play a major role in informing decisions about climate change adaptation.