PORTLAND, Ore. (AP) — A slow-moving and potentially record-setting heat wave is spreading across the Western U.S., the National Weather Service said, sending many residents in search of a cool haven from the dangerously high temperatures. The Southeast and Mid-Atlantic regions of the U.S. are also sweltering, with oppressive heat and humidity expected to last through Saturday.

Widespread temperature records are expected to be tied or even broken during the heat wave, with much of the West Coast likely to see triple-digit temperatures that are between 15 and 30 degrees Fahrenheit (8 and 16 degrees Celsius) higher than average, the National Weather Service said.