The one thing you obviously can't do in dealing with an excitable person is to lose your temper. The most important time, and the hardest time, to control your temper is when the other fellow has lost his. When the other fellow starts raising his voice lower yours. In dealing with hot-headed people, it pays to do a lot of listening. Let them blow off steam, cool down and reconsider.
Temperamental people are usually rather proud.
That makes them very susceptible to praise, Use it liberally wherever you can. Praise will usually calm anger quicker than anything else. Don' t carry grudges and do your best to keep others from nursing grudges against you. When you've had trouble with people don't hesitate to make the first move toward apologizing. Most people are more than willing to let bygones be bygones.