When the temperatures rise outside, most of us go inside. But, the threat of 120-degree weather is proving to be sort of a siren call to thousands around the world.

For instance, business is booming in Death Valley where visitors experienced 124 degree temperatures on Sunday.

Mike Orozco works at Panamint Springs Resort, near the entrance of Death Valley National Park. He said hotel rooms are in high demand right now especially with tourists from outside the United States.

“When it's 120 to 125 (degrees), there's more customers than there ever is," Orozco said. When summer spikes, locals call it “European season," Orozco joked.

Tourists come mainly from Germany, France, Sweden and other regions of Europe to experience heat never felt in their area of the world.

The National Weather Service has forecasted temperatures could climb even higher than 124 by midweek.

Getting home may be tourists’ most difficult challenge. When temperatures climb above 115, pilots warn air density changes and lift off is harder, which could delay flights for Las Vegas’ McCarron Airport and Phoenix Sky Harbor.