Mount Washington, New Hampshire
Despite the outsized-seeming boast that this otherwise unassuming peak is “Home of the World’s Worst Weather,” unwary visitors every year learn the hard way that Mount Washington is certainly a contender for that title. Take the fact that even when it’s a sunny hot day in the area, shorts-wearing explorers will discover that the summit is likely freezing: on average it’s a frigid 27 degrees, and the thermometer has never even ventured above 72. As a result more than a hundred climbers have succumbed over the years from any manner of weather-related mishaps, from exposure, avalanche, or being blown off a cliff (the mountain also holds the wind-speed record of 231 mph).
Bright Angel Trail, Grand Canyon, Arizona
That the Grand Canyon might present visitors with some challenges should surprise precisely no one. But until you’ve actually made the visit to and then down in, you may not appreciate how extreme the environment can get. And the most notorious hike is the 9.5 mile Bright Angel Trail that runs between the North and South rims. On paper it’s not a bad run, until you consider that temperatures regularly pop over 110 and that the approach is a long steady, draining, uphill slog. Despite plain warnings everywhere, some 250-odd people a year need to be rescued from the trail for heat-related ailments – so many that the National Park Service assigns a specific crew just to keep tabs on Bright Angel visitors.