Heat wave to bring triple-digit temperatures to more than 100 million Americans

More than 100 million Americans will experience stifling temperatures as a sprawling summer heat wave pushes thermometers into the triple digits later this week. This marks the second time in a month that severe heat has affected the United States. Temperatures reached 116 degrees in Phoenix earlier this month.

Heat dome movement The heat dome, a high-pressure system that traps hot air over a region, is moving east after breaking records in the Rockies and Great Plains. Temperatures in the Northeast are expected to peak on Wednesday and Thursday before improving moderately by the weekend.

The Washington, D.C., area will face some of the hottest temperatures on the East Coast. Residents can expect highs of up to 101 degrees on Wednesday and Thursday, according to the National Weather Service.

Local response and safety measures The mayor could activate an extreme heat alert, as done during the heat wave earlier this month. That decision would warn the public to avoid strenuous outdoor activities and remain in indoor, air-conditioned spaces.

It would also advise residents of emergency shelters and cooling centers. In extreme heat, health officials recommend frequent hydration, loose-fitting clothing, and sunscreen. Pets and small children can be particularly susceptible.