Stay calm no matter what; remember you're not the irate person.
Be polite and courteous don't allow the person to change your demeanor.
Speak calmly and completely.
Attempt to find out what the person's problem is.
Try to understand the persons view without agreeing or disagreeing.
Act sympathetic even if you're not.
Don't ask to many questions that will just irate the person more.
Resolve the persons issue if possible or give them directions to resolve.
Let them know they can call on you for more assistance if needed.
If person starts to aggravate you excuse yourself for a few minute, this will give you both time to settle down.
If person aggravates you and there is no compromise ask a supervisor, coworker, or friend for assistance.
If not a customer, avoid the person by not engaging them in any common interests.
Remember your health and family is most important.Have you ever had to deal with a person that was so irate that it ruined your day? How about a person that you just wanted to smack to straighten out? Well before you upset yourself, get yourself sick, or in to trouble here is a couple to tips to help you cope. Remember some people are just miserable that doesn't mean you have to be.