All across the country, people are eating spoonfuls of hot sauce. Straight. It's one of the many challenges participants take on during Xperience Adventure's urban races, which are part scavenger hunt, part obstacle course, and part 5K. They're also, like any good Texas birthday cake, part spicy.

The stars of each race are the teams of explorers. Guided by their smartphones, they careen through the city, sometimes on foot, sometimes on public transit. (Route strategy is a major factor in who wins.) They're trying to reach checkpoints, win challenges, and scavenge scavenger-hunt items at a good clip. It's a chaotic, many-pronged mission—and perhaps that's why, while the race unfolds, the city has the energy of a party.