A massive heat wave continues to broil many parts of the United States, with temperatures topping 100 degrees for the third straight day in many places. And with high humidity and other factors, the heat index shows that the temperatures often feel even hotter.
Melissa Block talks with Lans Rothfusz, a meteorologist at the National Weather Service in Peachtree City, Ga., about how the index is calculated.
Copyright 2022 NPR. To see more, visit https://www.npr.org.