Tens of millions across US continue to endure scorching temperatures: "Everyone needs to take this heat seriously"

Visitors to Las Vegas on Friday stepped out momentarily to snap photos and were hit by blast-furnace air. But most will spend their vacations in a vastly different climate — at casinos where the chilly air conditioning might require a light sweater.

Meanwhile, emergency room doctors were witnessing another world, as dehydrated construction workers, passed-out elderly residents and others suffered in an intense heat wave threatening to break the city's all-time record high of 117 degrees Fahrenheit (47.2 degrees Celsius) this weekend.

Few places in the scorching Southwest demonstrate the surreal contrast between indoor and outdoor life like Las Vegas, a neon-lit city rich with resorts, casinos, swimming pools, indoor nightclubs and shopping. Tens of millions of others across California and the Southwest, were also scrambling for ways to stay cool and safe from the dangers of extreme heat.