Dying at Home on Hot Days: The Role of Small-Area Social and Environmental Factors on Heat Vulnerability to At-Home Mortality in Boston, Massachusetts

Climate change is resulting in heatwaves that are more frequent, severe, and longer lasting, which results in public health threats to both morbidity and mortality. This is especially true in the Northeast United States, where heat-related mortality is projected to triple if adequate climate change mitigation and adaptation strategies are implemented. A case only analysis was used to examine subject and small-area neighborhood characteristics that modified the association between hot days and mortality, and geographic weighted regression analyses were used to examine these relationships spatially. All deaths of Boston, Massachusetts residents that occurred at home from 2000-2015 were included in this analysis. Meteorological data were obtained from the National Centers for Environmental Information, while modifying characteristics were obtained from both the mortality records and geographic data sets. Compared with at-home deaths occurring on other warm season days, non-white individuals, areas with more high-rise buildings, and those living in more densely populated areas were more highly represented among those who died at home on hot days. The association between hot days and mortality varies within a city based on social and environmental parameters. These relationships will also be explored spatially to inform heat adaptation strategies. Understanding which individuals and neighborhoods are most vulnerable to extreme heat in a local area can inform heat preparedness strategies and implementation.