Dangerous Heat Wave in Arizona Disrupts Travel, Daily Activities

It was 118 degrees on Sunday in Phoenix.

A United Airlines flight operated by Mesa Airlines that was headed to Phoenix on Sunday was forced to return to Houston because of the weather; the temperature on the runway was so hot that the plane's tires were at risk of bursting if the plane landed, according to the pilot.

ABC News' Neal Karlinsky took a heat-measuring gun to a Phoenix-area playground Sunday, where the temp hit 118 degrees, where a slide registered at 185 degrees and a swing registered at 171 degrees. A car door handle reached 146 degrees.

The heat in Arizona was deadly this weekend; there were four heat-related deaths after people went hiking or mountain biking.