127 hours

When the sun starts to go down on the canyonlands of south-eastern Utah in the American west, it bathes the vast rock formations and caverns in a deep red glow. It’s beautiful.

But at night, if you’re alone, it can be a cold and frightening place. Particularly if you find yourself trapped in one of the deep ravines that split the sandstone monoliths in two. It would be difficult for anyone to hear you during the day – but in the dark, a cry for help would be met with only silence.

No one knows that more than 35-year-old Aron Ralston. In 2003, he had gone hiking, alone, near Robbers Roost – an old outlaw hideout used in the dying days of the wild west by Butch Cassidy. But while Ralston was climbing down a narrow slot in Bluejohn Canyon, a boulder became dislodged, crushing Ralston’s right forearm and pinning it against the wall.

For five and a half days, he struggled to get free until he was forced to do the unthinkable. Using a blunt knife from his multi-tool, he began amputating his arm. This month Ralston’s incredible tale of survival comes to the big screen courtesy of film-maker Danny Boyle, in his new movie, 127 Hours.

Ralston was raised in the suburbs of Indianapolis, Indiana, but moved with his parents to Denver, Colorado when he was 11. He was a bright student and after university he moved to Arizona to work for Intel. But the lure of the great outdoors was too strong and he eventually left his job and moved to Aspen, in the Colorado Rockies. There he would hike, ski and cycle. He also set out to become the first person to climb all 55 of the state’s mountains over 14,000ft, alone in winter