In the world of ultra trail, the Marathon des sables is one of the most famous races but also one of the most feared. Due of its extreme length - nearly 150 miles - the MdS is completed in 6 timed stages spread over 7 days. Moreover, the Sahara desert, where the race takes place, is particularly hostile and unsuitable for running : sand, rocks and dunes, make the travel challenging ; all in extreme heat (over 110 °F during the day) but with negative temperature once night falls. When Mauro Prosperi, a 38- year-old Italian policeman, flew to Morocco in 1994 to take part in the Marathon des Sables, he was ready...