As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAINS #2 WINDOW HEAT OVERHEAT CAUTION LIGHT ILLUMINATED AT CRUISE ALTITUDE. GROUNDED - YES. PERFORMED QRH PROCEDURE AND SECURED HEAT SWITCH TO OFF. AFTER 5 MINUTES TURNED HEAT ON AND HEAT FUNCTIONED NORMALLY FOR THE REMAINDER OF THE FLIGHT. ALMOST 90 MINUTES.