As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT CREW REPORTED UNCONTROLLABLE DUCT TEMPERATURE FOLLOWED BY A PACK OVERHEAT ON BOTH LEFT AND RIGHT PACKS. RETURNED AIRCRAFT TO ORD. FOUND BOTH RAM AIR INLETS BLOCKED WITH PACKED SNOW. REMOVED SNOW AND CHECKED PACK OPERATION AS NORMAL.