The recording was shared by BBC 2 on social media recently titled 'How not to go on Mastermind'.
In the video, Hegarty is invited by Mastermind presenter, John Humphreys to sit in the iconic leather-clad chair.
Mr. Humphrys asks Hegarty for his "chosen subject" to which he replies "hilarious jokes".
"This will be a very short round - here we go," said Mr. Humphrys.
"Where is the worst place to hide in a hospital?," asks Mr. Humphrys to which Hegarty replies "I.C.U."
A further 11 questions follow and the Grand Opera House in Belfast even gets a mention.
The clip was shared on social media to help promote Mastermind on the BBC iPlayer.