The study explores thirteen census variables previously shown to contribute to social vulnerability during heatwaves and their contribution to heat related mortality in Maricopa County. The variables include percent female householder (no husband present), percent householder living alone, percent householder living alone (>65 years old), percent foreign born, percent who work in construction, percent who work in agriculture, forestry, fishing and hunting, and mining, percent of people whose income in last 12 months is below poverty level, percent of households with no vehicles available, percent 65 years or older, percent Hispanic or Latino, percent uninsured, percent female and percent renter households. A principle component analysis with varimax rotation was used to construct composite variables from the 13 socio-economic models. The data reflect the principle component found to be the best predictor of heat related mortality during extreme heat events. The census data used was the 2012 American Community Survey 5 year estimates (2008-2012). The mortality data came directly from the Maricopa County Department of Public Health for a period from 2005-2010.

The methodology is fully detailed in the publication: Heat Death Associations with the Built Environment, Social Vulnerability and their Interactions with Rising Temperature, 2016, David Eisenman, Holly Wilhalme, Chi-hong Tseng, Paul English, Mikhail Chester, Andrew Fraser, and Stephanie Pincetl, Health & Place, 41, pp. 89-99, doi: 10.1016/j.healthplace.2016.08.007.