Abstract: The present invention provides system of active uniform and base station for sensing an aspect of the wearers environment or physiology. Active uniform (1) is comprised of uniform (3), electronic sensors (40) for sensing an aspect of the wearer's environment or of the wearer's physiology and an active tag (10). The system of active uniform (1) and base station (2) is used to collect data from wearers of the at least one item of active uniform which allows an assessment of the health of the wearer where said health assessment is subsequently used to enhance the survivability of the wearer. The active tag contains various components that allow it to communicate with the base station (2) including (i) sensor interface (80) for interfacing electronic sensors (40) to the active tag, (ii) a microcontroller (70), (iii) a data store (60) including flash memory, (iv) radio frequency interface (110), (v) at least one tag antenna (120) and (vi) a battery (100) and power management unit (90).