Why overnight temperatures make U.S. heat wave even more excruciating
A brutal heat wave will scorch more than half of the country this weekend. More than 190 million people across 34 states are now under heat alerts. Parts of the upper Midwest and areas along the East Coast could see temperatures that feel like 110 degrees. Temperatures in many cities may struggle to drop below 80 at night. This means the heat will increase at an even faster pace the next day. Kris Van Cleave reports.