A few years ago, my husband and a friend of his attempted the Three Peaks Challenge—climbing the highest mountains of Scotland, England, and Wales within 24 hours. This included scaling Ben Nevis, the highest mountain in the British Isles at 1,344 meters. It was sunny at the foot of Ben Nevis as the men, dressed in just T-shirts and shorts, started their ascent. As they approached the summit, however, the weather changed; they hit ice and thick fog and their skimpy clothing simply wasn’t enough. They made it down the mountain, but the challenge was off.