Heat Map (IMAGE) Southwest Research Institute Caption This heat map shows the difference in temperatures across San Antonio. Dark orange represents the hottest areas and dark blue represents the coolest. Southwest Research Institute and The University of Texas at San Antonio are collaborating to study the felt heat of San Antonio’s Historic West Side, which is considerably hotter than the rest of the city. Credit Southwest Research Institute/UTSA Usage Restrictions Images/Videos may be used by the public for educational and informational purposes only. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.