In Europe, the death toll from an unprecedented heat wave has topped 2,000 as forecasters warn dangerous levels of heat are spreading east. In Greece, firefighters have responded to nearly 400 wildfires this week, while temperatures in parts of Poland approached 100 degrees Fahrenheit.
Here in the United States, forecasters are predicting this week’s dangerously hot weather will continue into the weekend, with 85% of residents set to experience highs of 90 degrees or hotter.
Dramatic new satellite images from NASA show the largest reservoir in the U.S., Lake Mead, is at its lowest level since the completion of the Hoover Dam in the 1930s. The reservoir serves about 25 million people.