Temperatures in the Southwest topped 100 on Saturday as forecasters warned the extreme heat could last for days. In Las Vegas, where temperatures reached 115 degrees, an elderly man was found dead in his un-air conditioned house on Saturday from a cardiac arrest believed to have been from the heat. Las Vegas paramedics said they responded to two other heat-related medical calls, a callback to the 2005 heatwave that killed 17. Flights at Phoenix airports were halted on Saturday after the temperature hit 119 degrees—planes are certified to take off only up to 118 degrees. Excessive heat warnings have been issued for large parts of California, Nevada, and Arizona through Tuesday night.