A widespread and dangerous heat wave is building across the U.S., with triple-digit highs expected in the Southwest and Great Plains this weekend before spreading eastward under a dome of high pressure that meteorologists say could trap oppressive temperatures for a week or more.
Forecasters are advising people to stay hydrated and find places to cool off, warning of temperatures 15 to 25 degrees Fahrenheit (8 to 14 degrees Celsius) warmer than normal in many areas, including at night — especially bad for people's health because their bodies won't have a chance to recover. The heat dome is expected to affect as much as two-thirds of the continental United States.
