New heat records were set in dozens of U.S. cities last week, while temperatures in Death Valley climbed just one degree shy of the hottest temperature ever recorded on Earth.

The record-breaking temperature comes as Las Vegas is under an excessive heat warning which is expected to stay in place through at least Thursday, July 11. The NWS warned residents to expect "dangerously hot conditions for an unusually long period" in parts of northwest Arizona, southeast California and south central and southern Nevada.

A brutal heat wave that has gripped the West for days will shift eastward on the weekend, while much of sweltering Houston still lacks electricity.