The Vietnam Maritime Search and Rescue Coordination Centre said on October 31 that the sailor had been brought ashore for emergency medical treatment.
At 9.20 am on October 30, the centre received an emergency call from the Japanese-flagged Demeter Leader, which was travelling from Japan to Singapore through waters off southern Vietnam.
A crew member had developed sudden, persistent pain on the left side of his chest, accompanied by breathing difficulties and a headache.
Medical assistance provider International SOS assessed the sailor as having suspected acute coronary syndrome, putting him at risk of a heart attack and requiring urgent hospital treatment.
His condition deteriorated at one point, requiring oxygen support, prompting the ship's captain to request an emergency evacuation.
The rescue centre immediately provided medical guidance and instructed the crew on first aid procedures.
Under the direction of the Vietnam Maritime and Waterway Administration, rescue vessel SAR 272 was dispatched from Phuoc Thang Ward in HCM City with two doctors on board.
At 3.21 am on October 31, the rescue vessel arrived at the centre's pier in Phuoc Thang Ward, where the sailor was transferred ashore for hospital treatment.