Old vs new Heat Index (IMAGE) University of California - Berkeley Caption The long-used Heat Index table (top) underestimates the apparent temperature for the most extreme heat and humidity conditions occurring today (center). The corrected version (bottom) is accurate over the entire range of temperatures and humidities humans will encounter with climate change. Credit David Romps and Yi-Chuan Lu, UC Berkeley Usage Restrictions none 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.