The Scots host the Premier League club at Tynecastle on Thursday night in the first leg of their playoff.
"There's a great atmosphere and occasion and before you realise it you've lost two goals," McGlynn said. "That's the difficulty so we've got to get across that we don't get caught up in the hype, really focus on the job.
"The noise is going to be great so when you're talking to your teammates, you have to make sure the information gets through."
Hearts are currently second in the Scottish Premier League following a win and two draws from their opening three matches.