As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5880, IAH TO BTR - DURING CLIMB-OUT AT APPROXIMATELY FL030, THE FLIGHT CREW RECEIVED A NR 1 AHRS OVERHEAT MESSAGE. THE QRH WAS FOLLOWED AND IT WAS DECIDED TO RETURN TO IAH WHERE THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE RE-CONNECTED THE FRONT VENT FAN AND THE AHRS OVERHEAT MESSAGE CLEARED.