Extreme heat is among the leading causes of weather-related deaths in the US. Electrically-powered air conditioning can reduce heat exposure and thus protect human health. Due to rising demand and more frequent severe weather, electrical blackouts have become increasingly common. More frequent and intense heat waves are expected with climate change, so future blackouts may result in significant risks to public health, especially among children, the elderly, and the poor. Being prepared for blackout emergencies and reducing hazards may have important health benefits during heat waves. This research estimates the human health risk of concurrent heat wave and blackout events in the cities of Atlanta, Detroit, and Phoenix and examines the potential benefits of specific actions to reduce the impacts of extreme heat, including environmental changes, technological improvements, and behavioral changes. Models of regional climate, building interior heat exposure, and human health effects combine to simulate human heat exposure under heat wave and electrical grid blackout scenarios, quantify heat-related illness, and evaluate the potential for individual and institutional adaptive strategies to lessen the impacts of extreme heat. This project estimates the human health risk of blackouts during periods of extreme heat, which already take a heavy toll on public health. The outcomes of this research advances the progress of science through the development of a new approach to measuring indoor heat exposure and enhances national health through the testing of electrical generation, passive cooling, and behavioral adaptations to protect health during extreme weather hazards. This research further supports the development of new protocols for emergency response planning pertaining to heat risk monitoring and evacuation.
The goals of this project are to estimate mortality and morbidity associated with simulated grid failure events during heat wave conditions in the cities of Atlanta, Detroit, and Phoenix in response to current and future climate conditions, and to assess the effectiveness of specific environmental, technological, and behavioral adaptations in mitigating a growing heat hazard. These cities were chosen for their different climatic, demographic, and urban form profiles. The research makes use of a modified health impact function to capture the effects of concurrent heat wave and grid failure events on mortality and morbidity. Through the linking of regional climate and building energy models, in combination with information on the residential building stock and grid infrastructure in each region, the study assesses the relative benefits of emergency preparedness and hazard mitigation strategies drawn from several distinct fields: urban climatology, architecture, electrical engineering, public health, and urban sociology. The study supports the advancement of knowledge and methodological innovation in three principal areas. First, the development of a new heat exposure metric - individual experienced temperature (IET) - enables for the first time an individualized assessment of heat risk responsive to daily patterns of heat exposure. Through the monitoring of both ambient and indoor temperature and humidity for occupants of classified building types, in combination with data collected through wearable sensors, it will be possible to substitute individualized measures of heat exposure for regional ambient temperature observations in health impact functions, improving the quantification of heat risk. Measurement of IET further enables quantification of the elevated risk of heat illness during periods of grid failure, when air conditioning systems are inoperable. Second, the integration of regional climate and building energy models will enable assessment of environmental, technological, and behavioral adaptations hypothesized to reduce IET. The testing of specific heat adaptations directly informs emergency preparedness and hazard mitigation planning undertaken by local and state governments. Finally, the collection of survey data on behavioral responses to extreme heat expands our understanding of how populations with variable access to continuous air conditioning cope with conditions of extreme heat and provides a basis to identify and promote effective personal adaptations.
