A new one - delayed for heat

Currently in ATL trying to get to EWR. We were delayed a few min due to our inbound plane arriving late. But then the gate agent announced that that cabin is too hot and the pilot refuses to let us board. I’m sure this is a result of what happened in Vegas earlier this week.

They aren’t sure how to proceed and may either get a new plane or just wait. Gate agent is pleading on the PA that people not ask questions as he is sharing all the info he has.