One summer break during college, I went with three friends to the Grand Canyon for a rim-to-rim hike. Carrying a sixty-pound pack through suffocating heat, we trekked mile after mile, snaking down the Kaibab Trail and across the scorching canyon floor. At one point, I blacked out and awoke moments later with my friends gazing down at me. They pulled me to a safe spot, took the pack off my back, and had me eat Starbursts candy (sugar was just what I needed). That escapade could have gone very differently if I’d been hiking alone!