I have a 3rd round interview scheduled for tomorrow morning. Since yesterday afternoon, I've had a stomach bug and fever, to the point that I had to call in sick to work today for I think the first time in 5 years. I was hoping I'd be feeling better this afternoon, but it isn't happening.
At what point would you reach out to them to reschedule?
I'd call and ask them what they prefer - interview as scheduled (maybe a phone interview so you don't make anyone sick?) or push the interview back. I'd let them make the call and just hope for a miraculous recovery.