You might want to check out psychologist Elaine Aron's work on the Highly Sensitive Person (HSP) - it's not the same as "empath", but there's some overlap.
www.hsperson.com/I guess my question is this, is it possible some of us are so sensitive to the energies of others or our surroundings that we take in suffering and pain more quickly than most people?
I don't know the answer to that question. But I think it's an interesting subject. And if it's true for you, you may need to learn ways of noticing others' energy and responding to it but without getting triggered/overwhelmed. It sounds like both a gift and a challenge.
Has anyone experienced this feeling in a public place?
No, but I've met people and immediately got a bad feeling about them, and said "no, don't jump to conclusions too quickly" but they turned out to be untrustworthy. It seems to be particularly to do with trust.
I also get other "feelings" once I've established a relationship with someone, I had a "feeling" in the idealization phase with both uBPD former friend, and uBPD ex (where I found myself saying to myself, "wow, I like this person... .but not as much as they like me?"