First Officer reported suffering gastrointestinal distress after landing which precluded an immediate post arrival walk around. While the First Officer was in the lavatory; a brake fire was noticed by ground personnel and that information was relayed to the crew.

Narrative

The Captain preformed the pre-departure walk around in ZZZ. He said the tires were a little worn; but no cord was showing. We taxied out to Runway XXL in ZZZ and departed with no incident. We landed in ZZZ1 on Runway XX. We touched down on speed in the Touchdown Zone; minimal braking and full thrust reversers. We exited the Runway at Taxiway XX. We arrived at our gate and the Ground Crew gave us the chokes in signal and we completed the parking checklist. I was experiencing an extreme gastrointestinal distress and immediately rushed to the bathroom; with the intent to return for the post flight walk around.When I arrived back at the gate; the final Passengers were getting off the aircraft. The Gate Agent was talking to the Captain when I was going down to do the walk around. I heard the Gate Agent tell the Captain I was still down on the aircraft and he said no he is right here. He proceeded to show us pictures of a main wheel with a flat tire and the brakes glowing. We thought at first he was showing us a picture of a previous aircraft and had no idea it was our aircraft. Since it was obvious the fuse plug blew; I didn't go outside and accomplish the post flight due to Safety issues. Also the Fire Crew was on scene.