WASHINGTON (AFP) - The south-west of the United States sizzled on Saturday as a heat wave baked the region amid predictions that temperatures in some areas could approach all-time record highs.

The National Weather Service warned that the scorching heat could be life-threatening and that it was not expected to let up for the next several days.

It said one of the hottest areas would be Death Valley, with temperatures there expected to be near 130 degrees Fahrenheit (54 deg C) on Saturday, Sunday and Monday.

"Many locations will break daily records and even approach all-time records," the National Weather Service said on its website.

Death Valley holds the world heat record - 57 deg C was recorded here on July 10, 1913.

The states in the hot seat are California, Arizona and Nevada. Death Valley National Park is located partly in California and partly in Nevada.

Saturday afternoon, forecasters expected temperatures in Phoenix, Arizona, and Las Vegas, Nevada, to hit 47 deg C. In Palm Springs, California, 119 degrees Fahrenheit (48 degrees Celsius) are possible, they said.

In Las Vegas, 30 people at an open air music festival had to be hospitalised on Friday due to the heat, broadcaster NBC reported.