 About 10% of the U.S. populations under the National Weather Service's highest heat alert and excessive heat warning. In Oregon, temperatures expected to reach 100 degrees. Parts of California could see 115 degrees. In Portland, Oregon, city officials like Julia Comnes expecting heavy turnout at cooling centers. All kinds of people, often people who are living outside, but it's also people who don't have air conditioning at home and just need a place to cool off.