As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB COCKPIT TEMP BECAME EXCESSIVELY HOT. RAN QRH AND AFTER TRIM AIR SWITCH TURNED OFF REGAINED TEMP CONTROL. PERFORMED BITE TEST ON CABIN ZONE TEMP CONTROLLER. NO CURRENT FAULTS OR PREVIOUS FAULTS NOTED. REMOVED AND REPLACED CABIN ZONE TEMP CONTROLLER AS PRECAUTIONARY REF B757 21-61-02-4-0. SYSTEM OPERATES NORMALLY. A/C OK FOR SERVICE.