Recent record temperatures in the U.S. suggest that heat-related illness isn’t confined to the dog days of summer. Dr. Aaron Bernstein, the interim director of the Center for Climate Health and the Global Environment at the Harvard T.H. Chan School of Public Health, describes the symptoms to watch out for, particularly if you have a chronic condition like heart disease or diabetes, and explains what safety steps to take. He also tells Francesca Coltrera, editor of the Harvard Health Blog, who bears the brunt of potentially life-threatening heat-related illness and how local actions can help reverse this growing health threat.