Anyone know how to control the "Fight or Flight" response?

I have several years of martial arts training, however most of it was spent honing my self control instead of my actual combat prowess. I need to know if there is anyway to learn how to control adrenaline when a fight happens, so I can control the "fight or flight" response. I have seen enough fights to know that sometimes even a skilled fighter can freeze up if not trained well enough at controlling themselves. Any tips or ideas?