Sir Ranulph Fiennes is receiving medical attention at Marathon des Sables . Veteran explorer , 71 , has completed most gruelling stage of the desert race . Forced to lie down intermittently during only an hour so he could finish . Aiming to become the oldest Briton to complete the six-day ultra-marathon .
Sir Ranulph Fiennes is receiving medical attention at Marathon des Sables . Veteran explorer , 71 , has completed most gruelling stage of the desert race . Forced to lie down intermittently during last few hours so he could finish . Aiming to become the oldest Briton to complete the six-day ultra-marathon .