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50 CLOTHING TEST METHODS Grade II The symptoms of distress, discomfort, or pain have intensified and the mission is interfered with. Examples. Fatigue. The subject is too fatigued to carry on combat or return promptly from a difficult patrol. Low Temperature. A sleeping bag would be in this grade if it failed to provide six hours sleep at night, since the mission of a sleeping bag is to pro- vide sleep for at least this long a period at night. Irritant Gas. Subjects are not severely afflicted but the irritation prevents effective combat. Grade III Severe pain or disability has developed and attempts at pursuing the mis- sion must be abandoned and unless steps are taken to improve the situation, in- jury will ensue. Examples. High Temperature. Heat prostration is impending and the soldier in the desert can no longer carry on combat. Low Temperature. The feet of a soldier in a particular boot have become numb and further exposure may result in frostbite or more serious sequellae. Low Oxygen Pressure. The pilot of a plane in combat has been partially deprived of his oxygen supply. If the situation is not corrected at once, the consequences may be fatal. Grade IV Development of pathology, temporary orâ¢permanent. Examples. Poisonous Gas. Mustard gas has just been sprayed from a plane on inadequately alerted troops. Many burns will result but permanent damage will be minimal if proper anti-gas measures are instituted at once. Immersion. The feet of a victim have been exposed a sufficiently long time to develop immersion foot with permanent damage and need for amputation of toes eventually. Dietary Deficiency. Scurvy, pellagra, or beriberi has developed but un- der proper care the disease may be cured.
METABOLIC RATES FOR MILITARY ACTIVITIES Frederick R. Wulsin ⢠Section I Techniques for measuring metabolic rates in laboratory's are highly developed. It is not the purpose of this paper to discuss them, but rather to give the laboratory worker factual information about the kinds of work and stress involved in military service, so that realistic metabolic rates may be used in experiments and calculations related to military equipment. Army activities can be divided into two broad classes: those which involve a fairly steady work rate, and those in which the work rate is highly irregular. In the first class are a number of occupations which resemble those of civilian lifeâstevedoring, cooking, truck driving, repairing and servicing vehicles, road building, ditch digging, construction work, office work and so on. Marching at a steady, pace, with or without a pack, involves a very uniform output of energy ex- cept in so far as terrain may vary. Any particular activity in this group is usually carried on for several hours at a stretch, and as a rule the total output of energy per day will not exceed that for similar civilian occupations. When this is the case, it should not prove difficult to select appropriate metabolic rates for representing these activities in the laboratory, or to determine them afresh where necessary. In emergencies, however, men may be obliged to carry on these tasks day and night, to the limits of human endurance, sometimes with insufficient food and sometimes under fire. It would be surprising if such conditions of stress did not alter the metabolic rates of men engaged in any particular activity, in addi- tion to imposing burdens upon the nervous system. It remains to be determined whether the effects of such stresses can be reproduced and measured in the labora- tory. Other army activities, including combat, make highly irregular metabolic demands. The most intense physical work, as in moving over rough ground at a run with heavy equipment, alternates with periods of stationary waiting, firing, or &low careful movement. During the working phase, metabolic rates may rise far above possible oxygen supply, but these bursts of activity will be short: a man carrying a 50-lb. trench mortar part, or a case of ammunition, in addition to 40 lbs. of basic clothing and equipment, may have to dash forward uphill for 20 to 50 yards at top speed, but he must then lie still behind cover until a fresh opportunity to advance presents itself. There are also longer alternations, as when a man digs a trench and then lies still in it, or carries heavy burdens of supplies and ammunition over rough ground in the dark, perhaps for several hours, and then returns to watching and waiting. The rate of muscular work involved in these activities will range from the maximum performance of an athlete to almost complete rest. It is likely that maximum hourly totals will not exceed those reached in a hard college foot- ball game, and many hours may be passed in comparatively light muscular activity. It is probable, also, that the total amount of muscular work done per 24 hours in battle, if averaged for a large number of soldiers, would be found to lie within reasonable limits. To the extent that these assumptions are true, metabolic rates, which approximate the purely physical exertions involved in combat, can be select- ed for use in the laboratory. The battle situation is complicated, however, by factors which may render experiments based on these assumptions quite unrealistic. In the first place, 51
