‘Health, Environment and Training’: Guidance on conduct of physical exertion in hot and humid climates

Abstract

Background: Military operations and training in hot environments present a special set of challenges to medical personnel who must support them. Methods: Various meteorological parameters such as relative humidity (RH), ambient air temperature (Ta) and radiant temperature (Tg), were evaluated at training sites in a desert region. Development of a colour coded Heat Stress Prevention Decision Aid Tool was done using an existing guideline chart.Results: Temperatures were being recorded routinely by ordinary meteorological instruments mounted within a Stevenson Screen. Onsite measurements with a USB datalogger was found to be relevant in making a decision on suitability of weather for conduct of training. Heat casualties occur when the stresses imposed by some combination of environment, work, and clothing combine to exceed individual tolerance limits. Personnel may encounter high environmental heat loads while working outdoors; during road marches; and while carrying loads or undertaking mechanical maintenance activities. Preventive strategies cannot be expected to eliminate heat stress but should minimize its impact on training while preserving the health of personnel to the extent possible. Conclusion:It is recommended that onsite measurement of meteorological parameters should be done, and a decision tool should be utilized for arriving at a spot decision by junior leaders.

Considerations for occupational heat exposure: A scoping review

“…Further research into the consequences of occupational exposure to heat and high physical loads was conducted during World War Two in an attempt to reduce the growing amount of heat related casualties in the Pacific Theatre of War. The environmental conditions of warfare training and military operations increased the risk and incidence of heat illness under adverse weather conditions [27]. During this time, humidity and heat waves were frequent and posed an even greater risk for heat related illnesses and casualties [28].…”

“…metabolism. Failure of this heat regulatory mechanism could result in total cessation of heat flow from the body and cause many adverse effects, such as heat stroke and death [27,28]. Many heat acclimatization techniques and strategies for acquiring thermal tolerance, such as increased cold fluid hydration, biologically and chemically engineered clothing and even frequent induction of heat exposure, were deployed during World War Two in an event to reduce the amount of heat related illness and casualty [29,30].…”

Non-Invasive Physiological Monitoring for Physical Exertion and Fatigue Assessment in Military Personnel: A Systematic Review

“…The development of physical fatigue can be seen as a process. It combines multiple contributors (personal, environmental, and operational demands) into a single physiological response [26,27]. Accordingly, it can be assessed by the continuous monitoring of the physiological variables: determining the pre-conditions of fatigue through physical exertion and predicting physiological overload or bad health status when reaching physiological limits.…”