A misread map, a sudden storm, a forgotten headlamp - and suddenly a leisurely hike can become a treacherous endeavour. In the past decade, cheap but sophisticated navigation devices and mobile phones have led to shocking levels of overconfidence on the trail. On top of this worrisome trend, the increasing popularity of mountain terrain has led those seeking solitude - or adrenaline - into increasingly remote or edgy forays. Sandy Stott, the "Accidents" editor at the journal of the Appalachian Mountain Club, delivers both a history and a celebration of the search-and-rescue workers who save countless lives in the White Mountains - along with a plea for us not to take their steadfastness and bravery for granted. Filled with tales of astonishing courage and sobering tragedy, Critical Hours will appeal to outdoor enthusiasts and armchair adventurers alike.