As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN CLIMB, THE TEMPERATURE IN THE CABIN WAS REALLY HOT. PILOT PUT TEMP CONTROL OFF AND BLOWER HIGH. THEN SMOKE APPEARED IN COCKPIT. PILOT CAME BACK AND LANDED IN ST-HUBERT. MAINTENANCE CHECKED THE SYSTEM AND FOUND DUCT MELTED UNDER THE FLOOR. ALL RELEVANT DUCT WERE REPLACED, TSB AND WERE ADVISE AND ALL OF OUR FLEET WAS GROUNDED FOR FURTHER INSPECTION OF AIR CONDITIONING SYS.