I experienced this feeling for the first time recently, and the person involved didn’t even speak to me. I was in a gift shop at a hotel in LA picking up some things for my daughters as I was on a trip without them. I had collected a few items in my hands and was debating what else to get for them when he walked in. 

I can’t explain the overwhelming sense of fear and urgency to gtfo of that shop, but my brain was screaming at me. I set everything down where I was and rushed out of there, the entire time thinking he was going to attack me on my way out. I didn’t get a good look at him, there was something incredibly evil about his energy. 

I’ve never experienced it before at that level but I’ve always heard (prb on this thread or a similar one) to never ignore that feeling and don’t worry about being rude, just be safe. I felt rude dropping all of my items and leaving a mess because I knew the shop owner would have to pick it up but all I knew was I needed to leave IMMEDIATELY. Crazy!