What was found
LT EGT SLOWLEY INCREASED 70 DEG UNTIL THE CAPT TURNED ON THE ENG INLET HEAT, DUCT AND PROP HEAT. THE EGT DROPPED TO NORM. WHEN THE EGT STARTED TO RISE AGAIN AND THE PWR LVR HAD NO EFFECT ON THE DROPPING TQ, CAPT ELECTED TO SHUTDOWN THE ENG AS A PRECAUTIONARY ACTION AND DECLARED AN EMERG. AFTER LANDING, WITH TEMP OF -50 DEG BELOW 0, THE CREW HAD BOTH ENGINES PRE-HEATED. AN HR LATER, THE CREW STARTED LT ENG NORMALLY AND MADE T/O PWR ON ENG GROUND RUNUP. MX INSPECTED ENG FOR DEFECTS, NONE FOUND. A/C RELEASED FOR SERV, NO FURTHER PROBLEMS NOTED. SUBMITTER STATES, CAUSE WAS FROZEN P2T2 BELLOWS. CREW WAS ADVISED TO TURN ON INLET HEAT IF ANY SIMILAR INDICATIONS ARE RECEIVED.