Sunglasses Spark Cockpit Fire

April 21/14-A Pacific Coastal Airlines Beech 1900 (C-FPCO) flight PCO135 taxied to position for take-off from runway 26L in Vancouver (CYVR). The pilot’s sunglasses, having been left on the glareshield, shorted out the windshield heat system causing smoke in the cockpit. The airport ARFF responded. The aircraft was inspected by maintenance and returned to service.