Armored Medical Research Laboratory Fort Km ox , Keinituckv Partial Report On THE ADEQUACY OF ARliOi?ED FORCE WINTER CLOTHING information copy Action copies have been forwarded to meats Section. AGP for approval and execution. Project Nos. 1-1, 1-4, 1-5, 1-6 January IB, 1943 ARMORED FOnCS MEDICAL RESEARCH LABORATORY Tort Knox, Kentucky Project Ron. 1-1, 1-4, 1-6, 1-6 Pile Ho. 727 January 16, 1943 PARTIAL REPORT OH THE ADEQUACY OP ARMORED FORCE WHITER CLOTHING 1. PROJECT: 1-(1,4,5,6) Test of the Adequacy and Ranges of Use of Vinter Combat Clothing. £• Authority - Letter Commanding General, Headquarters Armored Force, Fort Knox, Kentucky, 400.112/6 GHOHD, dated September 24, 1942. b, Purpoaq - To determine the adequacy and ranges of use of Armored Force Winter combat clothing. a. aaowsia* a. Methods - The studies were carried out in the cold room at temperatures ranging from 410° F to -30° f, experiments were conducted for the most part In still air, so as to provide the least severe cooling conditions likely to be encountered. Details of the experimental proce- dure and the data obtained are given in the appendix. 3. gffCW?IgpS: &. The Armored Tore# winter combat uniform consisting of combat jacket; trousers; combat helmet, winter; overshoes, 4-buckle, arctic; and gloves, flying; supplemented with 2 suits of woolen underwear; 3 pairs of woolen socks and other articles of personal equipment (OD trousers, etc.,); will keep resting men warm for one (l) hour at an average temperature of 'jLg 7 —- Ti-i .1 ii-t “■ " ' • tMwaMW b.. The winter combat uniform is adequate for men doing moderately hard work at temperatures as low as -20°F., but only while the men keep working. £• Tentllatlon of the winter combat uniform fsTnadequate to pre- vent accumulation of moisture. Ventilation can only be secured by opening the jacket and overalls. The lower part cannot be ventilated. £, Defecation and urination require excessive exposure ef the body 1 e. The fastening of the winter combat helmet Is poor, The helmet fa cannot be fastened if gloves are worn, X* b©l®et does not provide sufficient protection for the face and neck* £, Hone of the issue gloves or combinations thereof were adequate at the temperatures of this study. h. Even when supplemented vlth 4 pairs of socks (1 cotton, 1 medium I wool, and 3 arctic) In the 4-buckle rubber arctics, protection for the feet v I was inadequate for more than one (X) hour at rest at -30° f, The toes were ) \ in danger of freezing within an hour, X. Knees are poorly protected and frequently cause as much dis- comfort as do^tEcTtoes. X* Supplementing the winter comoat uniform an indicated below will keep sitting, resting, men comfortably warm in quiet air, (with occasional breeze) for periods up to one and one-half hours at the temperatures noted. The limiting factor in most instances is the lack of sufficient protection for the feet and hands. v/ Tapp»ratmti9 0° to -M°T (1) Two pair wool socks, arctio (2) Parka, alpaca lined (windproof outer cover hood is also lined with alpaca) (3) Toque (4) Wool gloves (5) fur mittens (these are not practical, for the purpose of the experiment they were used to keep the hands warm enough to continue the test). -X09 to -30°y (1) As above (2) Turtle-neck sweater (3) Innersoles 4. SSOOKMBHDATION^ &• That the present Winter Combat Uniform with modifications, be retained pending the initiation and completion of experimental studies on new models. This recommendation is extended since the difficulty with the present suit lies primarily in the inadequate protection of the extrem- ities. That types of clothing other than those now Issued be investi- gated for their suitability to the needs of the Armored force when operating 2 In snb-freezing environments, c. That when arctics are worn, arctic socks and Innereoles be substitute.! for GI shoes which are contra-indicated during cold weather. d>, S'hat medium length arctic sock or equivalent be standardized. That until more complete studies are carried out, the present winter combet uniform be modified in the following respects; (1) Provision be made for defecation and urination without \ excessive exposure being necessary, (2) That openings be provided on the left side of the trousers similar to those on the right. (3) That zipper tabs be provided with thongs that can be handled with gloved hands. (4) That a suitaole fastener be provided for the chin strap on the combat helmet. Fasteners of metal should not be . with the ekinpand should be' capaBle of being} gloved hands, (Hole: Winter Operations Board urgently requested this change 10 months ago 1) • £, That the following changes be made in the parka, alpaca lined: (1) \jfa\e belt be attached. (2) The zipper be provided with thongs, (3) The facepiece be provided with fasteners capable of being easily fastened with gloved hands. (4) The present breast pockets be lined with alpaca or other material to provide auxiliary protection for the hands. (5) Additional pockets in the lower portion be added. .Submitted by: 1st Lt. Steven M. Horvath let Lt. L. W. Bichna APPROVED; WILLAHD machlb Lt Col, MC Commanding 3 appendix 1. INTRODUCTION: Many clinical studies on men who have experienced prolonged cold have shown clearly that the desire for warmth is overwhelming. Men will not endure severe cold with suffering even if it means sacrifice of duty. If warmth cannot be obtained, deterioration Is rapid and there is complete indifference to danger and responsibility. r* Clothing should be adequate to maintain an average body skin ten- v,perature of from 85° to 93° T. When the average skin temperature drops below this point, discomfort begins. With skin temperature below 80° F on '\ the torso, and toe temperatures of 47° or 48° F, there is marked discomfort, I The latter temperature is near the critical temperature for the toes. If the skin temperature on the toes remains at 45° F for aore_than an hour, * injury~may'~ehsue, below 40°~F frostbite may'^dcur^at"anytime if the exposure > is continued. Despite clothing, some fall of skin temperature and/or rectal tem- perature is inevitable with exposure to cold, but no clothing should be considered satisfactory for use by the Armed Forces unless it will protect men sufficiently to prevent the temperature of the skin of the trunk from falling below 85°F or the skin of the extremities below 65° F. Such criteria should be met by test under the conditions in which the clothing is to be used. Jfff men are to be transported at_rest in vehicles, or be confined with- in armored vehicles for periods of hours, the^’^ETr^Slothing ought to be ade- quate to prevent suffering when tested under these conditions, The clothing must, moreover, be so designed as to permit operation of the vehicle and its weapons. 2. aXPSHUCBBTAI. PROOBDUfig: In this first set of experiments an attempt was made to reproduce conditions that will be encountered by men who are forced by the nature of their duties to restrict their activity. The experiments were conducted in a refrigerated room with temperatures between f 10° and -30°F. The greatest portion of each experiment was conducted in still air so as to provide the least severe conditions for the cooling of the body, (Additional experiments are being made during which crews of various types of vehicles are exposed to wind velocities reaching 50 M,P,H.), /The clothing was worn by men who sat until they became too cold to continue. They were then walked around the room at a rate of approx- imately 2.5 miles per hour until warmed up. In most cases they again sat until they became dangerously cold whereupon the experiment was Skin and rectal temperatures were measured and subjective estimates of com- fort and shivering were obtained periodically. 1 Reaalt9j The first experiment, conducted at an average temperature of T,, indicated that the Armored Force Winter Combat Uniform is not adequate for maintaining resting' sen in comfort for periods much longer than on* hour. In 3 out of 4 cases shivering occurred within one and one-quarter (l£) hours. The uniform, however, proved quite adequate as long as men were engaged in moderate activity. Additional observations showed that this uniform would keep men comfortably warm at temperatures as low as -10° to -20° f,, if the men were engaged in moderately hard work, jComfort could only be maintained by continued work. Since Armored Force personnel must operate at temperatures as low as -30° F., a number of experiments were conducted in still air at temperatures of 0°, -10°, -®0° and -30°F. In these experiments the Combat Uniform was used as a basis to which other articles of clothing were added. For the ex- periment at 0°F,, an alpaca lined parka, two pairs of wool socks, arctic, and 4-buckle arctic overshoes were added. A generalized statement of the symptoms observed at 0°F follows in order of appearance: Knees - cold within one-half (£) hour. Toes and heels (and in some cases feet) cold within one (l)hour, Toes are painful y cold within one end one-quarter (ij) hours. Shivering, in some cases vigorous, within one and one-half (l£) hours, Walking became necessary for warmth, In general, the subjects warmed up after 15 minutes of walking. 7, After one-half (£) hour of walk ng the subjects were able to sit again with reasonable comfort for another hour. However, some |man cooled off very rapidly after the exercise. This point will be discussed In detail later. The addition of the alpacn lined parka helped greatly in keeping the body warm. The extremities were the first to suffer from the cold and caused the greatest degree of discomfort. There is a definite need for further study of means of protecting the extremities. The clothing used at 0° f was also tried at -10° F, The results were similar, with one major exception. The body cooled off rapidly and after 1 hour in one ease and 1-J* to 3 hours in the others. The subjects were uncomfortably cold, were shivering vigorously and had to walk for a longer period to get warm. On returning to the resting position, they cooled off very rapidly and had to retire from the experiment within 45 minutes due to extreme pain in the extremities. The presence of dampness and formation of s frost on the surface of the arctic overshoes appeared to be a large * contributary factor to this discomfort. For tests conducted at -20° F,, a turtle neck sweater was added to the combination of clothing worn at -10° F. Some of the subjective responses 2 of a. subject, L, B,, at ~30* J*. are presented in Protocol j1• Bote that the extremities were again the first to cool and that with continued exposure the pain and discomfort resulting from the cold extremities w«~e outstanding symp- toms and held the primary atte tion of the subject. Attention was focused on his uncomfortable extremities and Interest in other events suffered. The body began to cool within an hour but was relieved by shivering frornjiontinning its downward tre dL This sub je c t’’liaS' only a s 1 £g5T^'T6v body temperature (probably being kept elevated by his shivering). (Fig. I). The rapid and. extensive alteration in the skin te erature of the toes, a 50 degree dropL in approximately one and one-half (l|) hours, is typical for the insulatlvei— protection given to all of our~suB'jecTs* extremities. L. 1. feet (toes particularly) warmed very slowly during his walk. At the cessation of 60 minutes of exercise the skin temperature of his toes had been raised only 22 degrees f. However, they were in a fairly comfortable range and his subjective reactions indicated warm toes. It whould be noted that subject- ive sensations are only indicative and may be far from actual values, usually they lag behind recorded tem eratures of particular areas. It was again noted following the exercise that the arctic overshoes were damp. This of the arctics is the primary reason for their as protective fodfwiar in coTST The leads to more rapid cooling of the toes and foot since^at¥r Ts an gfficientT conductor of heat. Experiments were also conducted at -30° F, The clothing worn was similar to that used at -20° with the exce ption that burlap or felt innersoles were added to provide additional protection for feet. This experiment was conducted after a period of mildly cold weather. All of our subjects but one had practically identical responses. Toes, knees, heels and fingers were quite cool within the first twenty minutes of exposure and shivering was vigorous at the end In one subject, shivering started after 15 minutes of exposure and rapidly became quite violent. Despite excessively hard shivering, his extremities were painfully cold at the end of one hour. All but one subject (W, J., who did no walking), walked for 20 minutes which was sufficient to elevate the temperature of the toes to comfortable levels. On returning to a sitting position, there was a ra:>id cooling of the extre- mities and of the body. Shivering became vigorous despite which the toes became so unbearaoly painful that the experiment had to be terminated. One subject, (W, J., fig II), was able to remain sitting quietly for two and one-half (2£) hours. During the hour there were no symptoms of cold except for slight chilliness of knees and fingers. After that the toes began to cool off rapidly and by hours the thighs, as well as the fingers were quite cold. There was a slow steady decrease in his rectal temperature, a fall of _2. 08T. ffflM skin temperature of the chest remained con- stant for nearly two hours and then began to fall. The skin temperature of his great toe fell slowly but steadily. At the end of two hours and 25 minutes, it had dropped to levels of severe discomfort and the subject had to leave the room. The skin temperature of index finger and the palm ware practically identical for the first hour and then began to diverge, the index finger be- coming colder while the palm leveled off. 3 In Tig, III it shown the rather atypical response of one of our subjects. He vat the only subject that did not complain to any great extent of cold at -10® T and was experiencing no apparent discomfort. WhlTe there was a drop In the temperature of his extremities, it was not extreme. The skin temper- ature of the suojeot*8 toes after 2 hours was 66® if while after the same In- terval of time in other subjects the toe skin temperatures were as low as 46° f. An explanation can be found in the rectal (or body) temperature changes. H.G.*s rectal temperature dropped approximately 3° f In contrast to falls of not sore than f In any of the other subjects* COMMITS OK THE CLOTHING TESTED: The primary defect of Armored force Winter Clothing is the Inadequacy of the protection given to the extre- mities. The question of gloves is particularly pressing and vital, since it affects all personnel especially those whose work entails delicate manipula- tions. The feet are another poorly protected portion of the body, and better means of protection must be devised. Whether this can be accomplished by better insulation, or by heating the toes with electrically heated socks is unimportant. The need for*lnpdTecir9h"rs" uee^F^oes^in gold weather is definitely contraindicated. The ’ shb¥~ A CP TEMPERATURE °C TIME — HOURS CLOTHES WORN I PR. 4 BUCKLE ARCTICS 1 PR. G.I, WOOL SOCKS 2 PR. ARCTIC WOOL SOCKS I TURTLE NECK SWEATER I PR. COTTON SHORTS 2 PR. WOOL UNDERWEAR I COMBAT UNIFORM I PARKA, ALPACA I TOQUE I PR. FUR MITTENS I PR worn ri ovfr RECTAL HAND, PALM INDEX FINGER CHEST TOE Fig. II Fig. HI BODY AND SKIN TEMPERATURES (SUBJECT H.G.) SITTING AND WALKING AT-IO°F. 11-20-42 TEMPERATURE °F TEMPERATURE °C i Walking I TIME- HOURS CLOTHES WORN I PR. 4 BUCKLE ARCTICS 1 PR. 6.1. WOOL SOCKS 1 PR. ARCTIC WOOL SOCKS 2 PR. HEAVY WOOL SOCKS 1 TURTLE NECK SWEATER 2 PR. WOOL UNDERWEAR I COMBAT UNIFORM i parka, Alpaca I FUR TRIMMED PARKA I PR. FUR MITTENS I PR. WOOL GLOVES RECTAL TOE INDEX FINGER Fig. HI