Heat Vulnerability

Heat and Social Inequity in the United States

Four Twenty Seven has developed a series of maps that examines one of the most significant public health risks posed by climate change: heat vulnerability.

These maps combine projections from global climate models with socioeconomic indicators of heat vulnerability to compare the complex and interconnected components of heat risk and resilience by county in the U.S.
The maps can be used to discuss climate change impacts on public health with doctors, nurses and other professionals in the healthcare sector. Public health officials can focus on a county of interest and identify key drivers of vulnerability as a starting point for planning and evaluation. The maps can also be used to engage the community and help improve preparedness ahead of heat events in the short- and long-term.

The application contains five interactive maps. The first four maps let you explore the determinants of heat vulnerability that compose your county’s vulnerability to heat. The fifth map displays a new composite indicator developed by our team, the “Heat Vulnerability Score,” to help identify counties most vulnerable to negative health impacts due to extreme heat.

Explore the app here:

Heat and Social Inequity Tool Screenshot


The methodology developed by Four Twenty Seven for this project and underlying data may be accessed here.

This application was developed as part of Four Twenty Seven’s commitment to the White House Climate Data Initiative, an ambitious effort that supports the development of data-driven planning tools to build resilience to climate change impacts in local communities. The tool has been peer-reviewed by CDC and NOAA, and is now featured on NOAA’s Climate Resilience Toolkit.

Commit to getting informed. Email climate@427mt.com or call (415) 930-9090 to learn more about what climate change means for your organization.