The Marathon Des Sables is an iconic multi-day race in the Sahara desert which requires the 1,000+ competitors to cover around 150 miles on foot over 6 stages/7 days in semi self-sufficiency (bottled water for drinking and an open-sided 8 man “tent” are provided).  Extreme temperatures are to be expected and 50C+ is not unusual.  Food for the week and various bits of equipment must be carried in a backpack weighing anywhere between 6.5kg and 15kg and includes the long list of compulsory stuff such as a minimum of 2,000kcal per day, an anti-venom pump, signalling mirror and of course tropical disinfectant (causing many debates on the forums as to what it actually is!).