What was found
(CAN) ON ARRIVAL THE AFT SERVICE DOOR WAS FOUND FROZEN AND WOULD NOT OPEN. THE DOOR WAS THAWED AS THERE WAS A SIGNIFICANT BUILD UP OF FROST ON THE DOOR SEAL. THERE WERE NO MECHANICAL ISSUES WITH THE DOOR. SINCE THIS DOOR IS CLASSED AS AN EMERGENCY EXIT IT IS REQUIRED TO BE OPERATIONAL. IT HAS BEEN NOTED INTERNALLY VIA OUR SMS REPORTING, THAT THIS HAS BEEN A COMMON OCCURRENCE DURING EXTREME COLD WEATHER. ACFT TSN 2857, CSN 2110.