When someone is needlessly hostile, you have a choice: Stay positive or get upset and turn hostile yourself. Remember it's always best to keep your cool and handle the situation as calmly as possible. These tips may help:
The conflict will only escalate if you, too, become antagonistic, and ultimately, nothing will be solved. Take a deep breath, do your best to stay calm, and approach the situation logically.
Sure it's tough to smile and grit your teeth, but many times, a calm demeanor will defuse an attack. Being nice should allow you to get through a bad situation with the fewest emotional casualties.
Hostile people will aim their rage at anyone within earshot. Simply accept this and move on to try to reach an agreeable, peaceful solution to the situation at hand.
Just because you're doing your best to be nice and helpful, it doesn't mean the hostile person will back off. Some people are just nasty. But it doesn't mean you, too, have to buy into aggressive behavior.
Focus on the people and things that bring happiness to your day. Take the hostility as it comes, then put it behind you and forget it.