Monitoring core body temperature in infantry soldiers and airfield defence guards

During strenuous and/or extended exercise in hot environments, considerable body heat can be produced. If the heat produced is above the body's thermoregulatory capacities, or if these capacities are impeded, a rise in core body temperature (Tc) will occur. Infantry soldiers and Airfield Defence Guards within the Australian Defence Force (ADF) are often based in areas which expose them to high levels of thermal stress. Furthermore, they must perform physically demanding training and operations, often in full camouflage, and on occasions with a range of equipment including body armour, which further increases the risk of developing a heat illness during training tasks. The ADF is addressing this issue as part of the Defence Physical Employment Standards (DPES) project, which aims at developing new employment standards using tests that reflect job requirements, and in which soldiers and airmen will be required to complete a number of strenuous and/or extended physical tasks. Two high risk tasks involve marching for either 10 or 20 km at an average velocity of 6km/hr, wearing full camouflage and carrying a 45kg pack. A third high risk task, which simulates movement in urban terrain, is shorter in duration but higher in intensity, and involves wearing ballistic vest, helmet, and webbing. In order to enhance safety by decreasing the risk of heat injury associated with completing these three tasks, Tc is being monitored using telemetric pills. A subject who reaches a Tc of 39.5oC will be withdrawn from the task. Preliminary testing in reasonably mild environmental conditions (15-20oC WBGTO), resulted in steady increases in Tc throughout each task, though no subject's core temperature reached 39.5 in any of the tasks