In “Running Wild with Bear Grylls,” the survival expert escorts a celebrity to some of the most isolated spots across the United States and the globe for an unforgettable 48-hour adventure. Whether it’s parachuting into the Catskill Mountains, descending the sheer cliffs of Utah, or enduring fierce winds and rain in Scotland, Grylls and his celebrity companion must test their mental and physical endurance to triumph over the challenges of their expedition.