in one aspect , the present disclosure relates to improved cooling module of a type for circulating water or other cooling fluid through a tube - lined cooling garment system . in another aspect , the present disclosure relates to a central shaft for the transmission of rotational power or torque . in yet another aspect , the present disclosure relates to a hydration system which may be employed in connection with the cooling module described herein . in still another aspect , the present disclosure relates to an improved garment pass - through connection system for penetrating one or more garment layers .