 Number two. A heat wave continues to bake much of the U.S., including most western states, as nearly 140 million Americans are under heat alerts. Today, Las Vegas is on track to set a record for the most consecutive days over 115 degrees amid the city's most extreme heat wave ever. Triple-digit heat is being blamed for at least six deaths in Oregon. Elsewhere, the Houston region is set to deal with another day of humid heat in the mid-90s. Some of the area's cooling centers are running off generators.