A dangerous heat wave is building across the country, bringing hotter than average temperatures to the central and southern U.S., threatening records. Temperatures will be in the 90s and triple digits for millions, and this heat doesn’t plan on going away anytime soon. For September, these temperatures are not feeling anything like fall, with many seeing temperatures 5 to 15 degrees above average. In the South, the humidity will make temperatures feel even worse. Here’s the latest.