i am designing an armor in my head (along with hundreds of other things) and i want to know specifics about cooling systems. i've decided on a coolant system pumped by feet/arm movements/etc but i need to know: how effective are such systems? specifically, how long would they last, how cold can they get, etc? Of course i do not have a coolant being pumped around my armour constantly (i'd freeze just by standing still) i have a water like substance that passes by a main housing system that contains coolants. the temperature of the circulating fluid would be determined by the amount that it was allowed to pass by the coolant. i suppose a computer could control that. is there a system like this being utilized or one more effective?