On a family walk to the Rob Roy Glacier we were approached by a man asking if we were carrying a PLB. A visiting American tourist had collapsed further up the track. This area does not have cell phone coverage so the man was going to run back to the start of the track and then drive 10km to the nearest farm house to contact emergency services. We ran up the track until we came across the patient, and activated our ACR Resqfix beacon. The Wanaka Search and Rescue team arrived by helicopter and the patient was winched aboard. He was taken to a waiting ambulance in the valley where it was decided his condition was serious enough to call the rescue helicopter from Dunedin. He was flown to Dunedin and has made a full recovery.