Most of us are careful not to leave lit candles near the curtains or toss matches around the backyard, but if you have an irrational fear of fire, you've got pyrophobia. In some cases, pyrophobia results from a childhood accident with fire, but sometimes the cause isn't so clear. Someone with pyrophobia might feel dizzy, sweaty, or sick at the sight of flames. The Greek roots of the words are pyro, "fire," and phobos, "fear."