I'm going to cold-shoulder the kid who takes out the trash at my office
Who is this guy that you want to give a cold shoulder to?
That's my co-worker; I don't like him, I wish he wasn't my co-worker
You don't have to like all your co-workers but it is not good to give them a cold-shoulder. It will make you seem mean and people will think that you are not a team player.
It's alright if I'm not a team player as long as I get my job done.
Part of working is getting along with your coworker. Also by cold shouldering your coworker and others, it will make it harder to work together as a team on tasks needed in your job.