Measuring wet bulb globe temperatures at point-of-exertion in worldwide UK military settings: a longitudinal observational study determining the accuracy of a portable WBGT monitor.

INTRODUCTION: Heat illness among the UK Armed Forces is usually exertional, and therefore preventable, yet the incidence has not reduced since 2011. JSP 539 explicitly states that wet bulb globe temperature (WBGT) should be measured 'at the location of greatest heat risk', not 'that of most convenience'. A handheld WBGT tracker used at point-of-exertion could reduce this incidence if proven to be as accurate as the current in-service device. METHODS: Longitudinal observational comparison and equipment feasibility study of the Kestrel 5400 and QUESTemp 34 (QT-34) in worldwide firm base and deployed UK Armed Forces locations. The locations chosen were Kenya, South Sudan, Belize, Tidworth, Aldershot and Brecon. Paired data points of WBGT readings were collected from November 2017 to August 2018 in all weather conditions. RESULTS: WBGT readings were comparable between the QT-34 and Kestrel 5400 across the UK and overseas. In addition, there was no change in accuracy between readings taken from the Kestrel 5400 when tripod-mounted and handheld. The Kestrel was easy to set up and far less susceptible to resupply or power supply limitations, as it requires no user input for wet bulb temperature, and runs on AA batteries. CONCLUSION: This equipment feasibility study has shown that the Kestrel 5400 gives an acceptable accuracy and is easier to use than the QT-34. The authors recommend that the Kestrel 5400 is introduced as an adjunct to the QT-34, and its use within the military setting monitored through ongoing comparative data collection in a large-scale proof-of-concept study.

Developing a multimodal biosensor for remote physiological monitoring.

INTRODUCTION: Several UK military expeditions have successfully used physiological sensors to monitor participant's physiological responses to challenging environmental conditions. This article describes the development and trial of a multimodal wearable biosensor that was used during the first all-female unassisted ski crossing of the Antarctic land mass. The project successfully transmitted remote real-time physiological data back to the UK. The ergonomic and technical lessons identified have informed recommendations for future wearable devices. METHOD: The biosensor devices were designed to be continuously worn against the skin and capture: HR, ECG, body surface temperature, bioimpedance, perspiration pH, sodium, lactate and glucose. The data were transmitted from the devices to an android smartphone using near-field technology. A custom-built App running on an android smartphone managed the secure transmission of the data to a UK research centre, using a commercially available satellite transceiver. RESULTS: Real-time physiological data, captured by the multimodal device, was successfully transmitted back to a UK research control centre on 6 occasions. Postexpedition feedback from the participants has contributed to the ergonomic and technical refinement of the next generation of devices. CONCLUSION: The future success of wearable technologies lies in establishing clinical confidence in the quality of the measured data and the accurate interpretation of those data in the context of the individual, the environment and activity being undertaken. In the near future, wearable physiological monitoring could improve point-of-care diagnostic accuracy and inform critical medical and command decisions.

Chronic fatigue syndrome in the UK armed forces.

Chronic Fatigue Syndrome (CFS) is a debilitating condition that can have a significant impact on the lives of patients and those who care for them. In the UK Armed Forces this condition can also have a marked impact on a patient's career and their ability to function in the deployed environment. In this article the recognition and management of CFS will be discussed, as well as the occupational considerations within the UK Armed Forces.