Cork plays for the first time against Nottingham Forest tonight since being rushed to hospital at half-time during a friendly against Iceland a fortnight ago.
He said: "It was a bit weird seeing my resting heartbeat doing three beats a second.
"I went over 15 minutes before half-time and said, 'My heartbeat's really high and I feel really tired'. I felt like I was going to black out.
"I'm not sure what caused it. Fingers crossed it never happens again."