A California Toolkit for Heat Resilience in Underserved Environments


Extreme HeatHeat is increasingly brutal in California’s Central Valley, where low incomes, poor air quality, old homes, and high utility bills disadvantage many residents.  The good news is that we can act now on preventative strategies to mitigate heat health impacts. The multi-disciplinary Cal-THRIVES project has developed a cooling toolkit for local and state stakeholders below with the following objectives:

  • Increase awareness of heat-related vulnerability 
  • Identify areas that are vulnerable to extreme heat events
  • Remedy the built environment, such as building retrofits & increases to tree canopy
  • Enhance community and home cooling programs
  • Improve social capital and connectivity at the neighborhood level

Cal-Thrives Community EngagementOur research and heat-resilience recommendations incorporate both community inputs and science:

  • Community Engagement
  • Cooling center characterization and improvements
  • Neighborhood-scale building modeling
  • Outdoor measure modeling
  • Overview slides [pdf file]

Cooling Toolkit

Community Cooling Guides

Community Cooling Tip Sheet ScreenshotOne-page and pocket community guides detailing tips for staying cool in the heat are available for download in English and Spanish. 

"Tips to Stay Cool in the Heat" Community Guide

Community Cooling Pocket Guide 

Fact Sheets

Cooling measure fact sheet previewThe toolkit offers a collection of fact sheets about passive and active cooling measures, ideal for use with more specialized audiences like DIY-enthusiasts, NGOs and program administrators. 

Cooling Topic Fact Sheets

Modeling Results
Passive measure simulation chart
Click image to enlarge view

Modeling summaries for building and outdoor measures are available for extreme heat resilience program developers, engineers, and researchers. 

Modeling Summary Matrices

Software Tools

CityBES preview For extreme heat resilience program developers, engineers, and researchers, software tools are available to assist with neighborhood-scale building modeling. 


CityBES is an open tool for neighborhood- to urban-scale building modeling, which can model energy savings for one building or a group of buildings. Both passive and active indoor measures are modeled. 

Heat Vulnerability Index (HVI)

A Heat Vulnerability Index (HVI) modeling tool for Fresco is available online. 

Policy and Program Recommendations

For state, regional, and local policymakers, the toolkit offers policy and program recommendations. 

CA Strategic Growth CouncilThis toolkit was developed as part of the Cal-THRIVES project funded by the California Strategic Growth Council.

Related publications

  • Susan Mazur-Stommen. "Fresno State of Mind: Results from Heat Resilience Research in a Disadvantaged Community." Behavior, Energy, and Climate Change Conference (2020) [pdf file]
  • Yujie Xu, Tianzhen Hong, Wanni Zhang, Zhaoyun Zeng, Max Wei. "Heat Vulnerability Index Development and Mapping." Symposium on Simulation for Architecture and Urban Design (2021) [pdf file]
  • Kaiyu Sun, Wanni Zhang, Zhaoyun Zeng, Ronnen M. Levinson, Max Wei, Tianzhen Hong. "Passive cooling designs to improve heat resilience of homes in underserved and vulnerable communities." Energy and Buildings Volume 252 (2021) [pdf file]
  • Zhaoyun Zeng, Wanni Zhang, Kaiyu Sun, Max Wei, Tianzhen Hong. "Investigation of pre-cooling as a recommended measure to improve residential buildings’ thermal resilience during heat waves." Accepted for publication to Building and Environment [pdf file]


Lawrence Berkeley National Lab led the project and building modeling using CityBES

Indicia ConsultingIndicia Consulting social scientists led focus groups and in-depth individual interviews.

Susan Mazur-Stommen, Haley Gilbert



USCUniversity of Southern California led outdoor modeling using Envi-MET

George Ban-Weiss, Alexandra Bruce, Yuxi Liu, Kayley Butler


West Fresno Family Resource CenterWest Fresno Family Resource Center led for community outreach and phone surveys

Janice Mathurin, Yolanda Sue Randles




Welcome to FresnoWe also thank the Fresno Economic Opportunity Commission for energy assessment data and phone survey support. 







For any questions or further information on this project, please contact Max Wei ( or Ronnen Levinson (