Heat Surveys in Hot Places: Predictors of Heat Illness Events in Phoenix, Arizona

The determinants of spatial and temporal variability in heat-related mortality and morbidity have been the subject of extensive research in the hot, desert city of Phoenix, Arizona. Most researchers have focused on hospital records and autopsy reports to provide statistics on extreme heat exposure events, yet it is estimated that many more heat illness events go unreported. Social surveys can give us greater insight into the extent and drivers of heat illness, particularly in those events that did not result in formal medical care. Two residential social surveys recently conducted in the Phoenix Metropolitan Area specifically ask residents about their experience with heat illness, their perceptions of heat in their neighborhood, and their access to and use of cooling resources: the 2017 Phoenix Area Social Survey (n = 497), administered by the Central Arizona Phoenix Long-Term Ecological Research program, and the 3HEAT screening survey (n = 163), administered as part of an NSF-supported three city collaboration within the cities of Phoenix, AZ, Detroit MI, and Atlanta, GA. Survey responses indicate that indoor residential thermal comfort, financial constraints on air conditioning use, neighborhood scale temperature perceptions and land surface temperature observations, and risk perception of extreme heat are significantly correlated with incidence of heat illness. Thermal preference appears to be a more important determinant of indoor conditions and heat experiences than previously understood, and may mediate previously proposed associations between socioeconomic status and heat vulnerability. Our work highlights opportunities to integrate across social surveys to yield more robust insights into associations between behavioral and environmental factors and heat-related health events.