After being advised of an unconscious passenger the flight crew of a B767-300ER expedited a return to their departure airport for medical assistance; overheating their brakes on landing and suffering the meltdown of a number of main gear fuse plugs after gate arrival.

Narrative

Just as we were leaving center; the flight attendants informed us that a passenger had passed out and apparently had no pulse. We immediately declared an emergency and turned to the nearest field. Captain had the Relief Pilot assess the situation (a physician and one of the flight attendants -a physician's assistant- were with the patient) and then return to the cockpit.Everything was done according to SOP...Captain contacted Dispatch; fuel was dumped; checklists run (dump; overweight landing; emergency landing; required runway for 25 flap landing); and coordination for gate and emergency services at the terminal. Longest available runway flaps 25 (for the weight and conditions)/ auto brakes 4 and the ILS approach planned; briefed; and executed. A high speed arrival was coordinated with ATC and maintained until the downwind turn at 4;000. Touchdown was on speed; beyond the displaced threshold at around 100 FPM descent (observed by Relief Pilot). I used maximum reverser and kicked off the auto brakes at approximately 80 KTS. We turned off before the end to expedite the taxi back to the terminal for the passenger in distress. After gate arrival and while deplaning the sick passenger; we noticed a cloud of smoke. Maintenance personnel came up to the flight deck to tell us that the number 3 brake had flames coming out of it when he arrived at the aircraft (smoke cloud was from extinguishing the flames). We confirmed that the aircraft was properly chocked and released the brakes. Later; we were advised that a number of fuse plugs had melted on the main landing gear wheels.