A woman was reported with an ankle injury. Because of the prolonged evacuation and cold we requested an helicopter to support. Air ambulance was unable to get in due to weather, so an S92 attended. By the time it had arrived, the weather had deteriorated further and it was hampered by lowering cloud base. Team members also attended and were able to treat the woman and remove he rto below the cloud, from where she was finally evacuated by the S92 which had returned from refueling.