Western heat wave tightens its grip, threatening record temps for millions

An unusually intense heat dome is pushing dangerous, often triple-digit temperatures across the Western United States this weekend, with about 55 million people under heat alerts and highs forecast to reach as high as 118°F in Phoenix and 115°F in Las Vegas, among other hot conditions. Nights will remain warm, raising risks of heat-related illness, and cooling centers are opening in major cities like Los Angeles and Las Vegas. The heat is accompanied by extreme fire danger in the Pacific Northwest, where windy, dry conditions and ongoing wildfires prompt evacuations and smoke across several states. Scientists say climate change is making such hot spells more frequent, intense, and long-lasting.