 Over a third of the U.S. population is under the threat of extreme heat. CBS News Philadelphia meteorologist Andrew Kozak has the details. West Coast temperatures well into the upper 90s, low 100s, and that's, of course, including the desert southwest. Death Valley, California, all-time high ever hit back in 1913, 134 degrees, likely to hit 129 to 130 on Sunday. In Pamblona, Spain...