i get them when ever i get cold really fast. ie getting out of the shower or going outiside on a cold day. its a constricting feeling like im helpless and causes me to hyperventalate and become very frightened. its happened to me since i was around 4 or 5 and ive come to the point when i can control it but i cant really do anything, i just stand there and look petrified. what could have caused this?