Axios

Heat alerts are impacting nearly 150 million people in at least 21 states — and forecasters warn potentially deadly high temperatures may linger in many places well beyond the Independence Day holiday weekend.

The big picture: With July 4 holiday travel expected to hit an all-time high, record-breaking temperatures are set to continue for up to two weeks across the U.S. West — where 18 large fires are burning. "Dangerous" heat is expected across the South and Mid-Atlantic through the weekend and into next week.