Heat vulnerability index mapping in Wisconsin

Extreme heat can threaten the public’s health by causing both heat-related illnesses and fatalities.  Risk to heat-related illness and mortality is affected not only by individual co-morbidities and health status, but also the built environment, socio-economic status, and environmental conditions such as heat index and air quality.

To analyze heat vulnerability, the Building Resilience Against Climate Effects (BRACE) program in the Wisconsin Department of Health Services (WI DHS) has compiled a group of datasets to develop a Heat Vulnerability Index (HVI) for Wisconsin and for the Milwaukee region.  Mapping this index allows us to better understand the spatial distribution of populations most vulnerable to heat.  Learning where areas of high heat vulnerability are located can inform public health interventions.  The BRACE program has partnered with the City of Milwaukee Health Department and the Milwaukee Heat Task Force to facilitate the use of the regional Milwaukee HVI in program planning and outreach efforts.  Ultimately, identified high risk neighborhoods will receive targeted messaging during heat events.

Air conditioning is a known protective factor in preventing heat-related fatalities.  To address the need for cooling during extreme heat events, one public health intervention is to provide cooling centers to offer relief for those without air conditioning.  HVI maps can be used to identify areas of high risk, identify transportation options, and assure the optimum location for cooling centers.