In Arizona, 120-degree heat is building, and warm nights are pushing the danger north

In Arizona, 120-degree heat is building, and warm nights are pushing the danger north

Blistering heat is tightening its grip on the Southwest, with some Arizona communities staring down highs of 120 degrees Fahrenheit in the coming days. And the danger does not stop at sunset. Unusually high overnight temperatures limit relief and push hazardous conditions into states less accustomed to this level of heat. What's happening? According to the Weather Prediction Center, a heat wave is spreading out of the Southwest and into more nor…