Indoor Environments and Extreme Heat Sensitive Health Outcomes in New York City, NY

Most extreme heat studies relate outdoor weather conditions to mortality and morbidity. However, many at-risk populations are exposed to extreme heat inside of buildings. In developed countries, people spend approximately 90% of their time indoors. Indoor temperature and humidity conditions widely vary across households despite equivalent outdoor conditions. Sealed buildings may magnify outdoor extreme heat exposure. The composition and configuration of the built environment, sociodemographic characteristics, and human actions and behaviors further alter outdoor/indoor linkages. A review of 96 papers found only a couple of studies that explicitly linked indoor heat exposure to human health (Anderson et al. 2012). We present an innovative observational study design to associate indoor conditions to extreme heat health outcomes. This pilot study directly measured indoor temperature and humidity of New York City, NY USA buildings where individuals receive emergency medical care. The study took place during August 2013. Objective morbidity information may be more reliable than self-reported health status and can provide the strongest evidence for developing extreme heat warnings.