On our fifth wedding anniversary, my husband and I climbed a difficult route on one of the granite faces of the South Bubble in Acadia National Park. Several hours into the climb, we were hot, thirsty, and tired, but nearing the top. My husband was leading and had mastered the final difficult move, leaving me roped up below him, about 300 feet from the ground. Suddenly I knew I was going to faint, hollered out a warning, and then passed out cold, swinging from the rope.