On the real-time prevention and monitoring of exertional heat illness in military personnel.

The proliferation of user-friendly low-cost wearable sensors has brought the concept of real-time physiological monitoring for exertional heat illness to the cusp of reality. This paper reviews and discusses the current state of the art in real-time physiological status monitoring for exertional heat illness mitigation within the military context. The review examines how both advanced sensor systems, models and algorithms are being combined in an international and collaborative way and how this is providing real solutions to military units to reduce the risk held by the commander. This paper provides additional detail into the process of integrating physiological status monitoring into military training, it explores the development of on-body sensors, the algorithms that can provide actionable information, the process of planning and dynamic risk assessment and describes some of the physiological monitoring systems that are currently being developed by the representative nations. It then discusses the knowledge gaps of how the technology will be integrated into military training, the importance of meaningful, accurate information that is both sensitive and specific and further developing the accuracy of the algorithms and models that are being employed. Finally, it talks about future direction and how individualizing physiological status monitoring can lead to performance enhancement in the form of individualized heat acclimatization programs. In conclusion, physiological status monitoring is at a stage of transition and integration where it can be used effectively to manage and reduce exertional heat illness to enable military personnel to train hard-train safe.

Telemetry pill measurement of core temperature in humans during active heating and cooling.

PURPOSE: This study compared the agreement between core temperature measurements obtained using an ingestible temperature pill telemetry system (Tpill) with those obtained from rectal (Tre) and esophageal (Tes) thermocouples under conditions of increasing and decreasing body temperature. METHODS: Four men and five women (age 25+/-2 yr, BSA 1.81+/-0.05 m2, VO2 peak 3.1+/-0.4 L x min[-1]) participated in four 3-h trials: cold (18 degrees C) water rest (CWR), cold water exercise (CWE), warm (36 degrees C) water rest (WWR), and warm water exercise (WWE). Subjects were immersed to the neck for each trial. During resting trials, subjects sat quietly. During exercise trials, subjects completed three bouts of 15 min of rest, followed by 45 min of exercise on a cycle ergometer at 50% of peak oxygen uptake. The temperature pill was taken 10-12 h before testing, after which the subjects fasted. RESULTS: The trials created conditions of constantly decreasing (CWR) or increasing (WWR) core temperature, as well as periods of oscillating core temperature (CWE and WWE). Root mean squared deviation (RMSD) was calculated for each pair of measurements (Tpill vs Tre, Tpill vs Tes, Tre vs Tes) for each trial. An RMSD of "0" indicates perfect agreement; as RMSD increases, agreement worsens. On CWR, the RMSD for Tpill-Tes (0.23+/-0.04) was lower (P < 0.05) than for Tpill-Tre (0.43+/-0.10) or Tre-Tes (0.46+/-0.09). There were no significant differences in RMSD between measurement pairs on any other trial (average RMSD = 0.26 degrees C). Telemetry pill temperature and response time tended to be intermediate between Tre and Tes. CONCLUSION: These results suggest the telemetry pill system provides a valid measurement of core temperature during conditions of decreasing as well as increasing body temperature and during steady state.

Post-categorical processing and attenuation of the auditory suffix: evidence from both immediate and delayed suffixes.

Recall of the final item in a spoken list is impaired by the presentation of a spoken to-be-ignored item following the list. The nature of the processes responsible for the stimulus suffix effect (as well as its magnitude) can be varied by manipulating the intrinsic characteristics of the relationship between the final list (target) item and suffix. A series of experiments show that systematic manipulation of both typicality of same-category membership of target-item and suffix (Experiment 1), and degree of synonymity between target-item and suffix (Experiment 2) result in differential attenuation in the magnitude of the suffix effect. The effect of the synonymity manipulation persists for up to twenty seconds after the presentation of the target-item (Experiment 3). That post-categorical processing of the suffix occurs provides direct support for semantic coding in short-term memory and contradicts models arguing that short-term memory is organised according to the principle of physical similarity (e.g., LeCompte and Watkins, 1993).