134 million people in US — including nearly all of West Coast — under heat alerts [Video]

Around 134 million people in the U.S. are under alerts as an “extremely dangerous and record-breaking” heat wave broils much of the country, according to the National Weather Service.

Regions that may see temperatures above 90 degrees or much higher into the triple digits include nearly all of the West Coast, the southern Plains, most of the lower Mississippi Valley into the Ohio Valley and parts of Florida, said Bob Oravec, a lead forecaster with the National Weather Service.

The Pacific Northwest will see the mercury rising later in the weekend. Arizona will continue to sizzle as firefighters battle a wildfire near Phoenix, where some contend with burns from blazing hot asphalt, concrete or other surfaces. And more humid regions will see a muggy weekend.

“If it’s both humid and hot, you can’t really rely on sweat to cool you down to a safe level,” said Daniel Swain, a climate scientist with the University of California, Los Angeles.

It’s a dangerous weather pattern hitting as fires burn in …