Perth -based air ambulance says he owes his life to the rescue crews who saved him. Duncan Stevenson was out walking with friends at Loch Tay near Killin in February last year when he suddenly suffered a heart attack.Due to the rural location and horrific weather conditions, the 57-year-old’s friends sought help from a nearby farmer, who rushed the group back to their hotel in the village, before frantically calling for an ambulance.