As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CONTROL WAS NOTIFIED BY MCI CENTER THAT THE CREW REPORTED SMOKE IN COCKPIT WHEN APPROXIMATELY 120NM WEST OF BUM VOR AND AT FL300 AND WERE DECLARING AN EMERGENCY. AFTER CLOCK IN, CAPT WINDSHIELD CRACKED. ISOLATED FUMES TO OVERHEATED WINDSHIELD. REMOVED AND REPLACED LEFT WINDOW HEAT CONTROL UNIT PER 757 AMM 30-41-01-4 TESTS OK. REMOVED AND REPLACED CAPTAINS WINDSHIELD PER AMM 56-11-01-4.