Traumatic injuries associated with adventure sports activities occur in hostile environment. The Femoral nerve anesthesia (FNA) outside of the hospital settings has been demonstrated but not in hostile environment. So, the objective of this study was to determine the feasibility of FNA for these very painful traumatized patients on the accident site and during their extraction-evacuation by helicoper. This prospective observational study was enrolled a convenience sample of 11 patients (4 women, 7 men) with closed fractures femurs. FNA was performed on all participants and 3 situations were defined (Impossible, Difficult if more than 1 attempt, Easy to perform). Pain evaluated using visual analog scale (VAS) (0-10) measured at the following time point: Rescue team arrival (T0), Ten minutes after FNA (T10), at Reduction of fracture (T Reduction) and during helicopter Evacuation (T Evacuation). The median age of the participants was aged 40 +/-18 years. The accidents which occurred were 7 Skiing, 2 moutaineering, 1 snowshoeing, 1 parapliding. 11 FNA performed with 5 fascia iliaca blocks, 6 femoral nerve blocks. 82% blocks were technically easy and 18% difficult. Pain evaluation showed an average VAS of 7,5 (7-8) at T0, 1,1 (0-2) at T10, 0,45 (0-1) at T Reduction, 0,36 (0-1) at T Evacuation. All the pathologies were treated with reduction and immobilization. Helicopter evacuations were conducted without incident in a calm atmosphere and with excellent patient cooperation. In final, FNA performed in difficult environment is feasible, effective, and reproducible in extreme conditions. There is no limitation due to hostile terrain. FNA techniques used must simple and fast but performed by trained physicians who are technical experts in order achieve a successful outcome in difficult terrain.