I was supposed to be doing an informational interview with an upcoming college grad now. She cancelled because she felt terrible. She said, “I've been feeling nauseous all day. I really wanted to talk to you when I'm at my best. Can we reschedule?”
You betcha we can. If I'm going to give my time to someone, I want to know they will use it wisely. I bet you do too.
If you're a hiring manager and you can't give the candidate 100% of you, postpone the phone screen or pull yourself out of the in-person interview loop.
If you're a candidate and you've got a bad head cold, please reschedule. If you can't get the nausea under control, please reschedule. If you have pneumonia, please, please, please reschedule. I don't want to get sick. I will respect you more for explaining you don't want to infect the rest of us. You need to give 100% of yourself to the interviewing process.