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Medical Science Publication No. 4, Volume II



Cold injury is the term applied to those conditions which result fromexposure of the body to cold. The type of injury that will be producedis dependent upon the degree of intensity of the cold, duration of exposureto the cold and the condition (dry or wet) of involved part at time ofinjury. Modification in the effect of any one of the three above factorsalters the type of cold injury that will be produced. Cold injury thereforeis divided into the following clinical entities:

1. Frostbite. The duration of exposure varies from a few minutesto 16 hours in ambient temperatures ranging from +20° F. to -80°F.

2. Trench Foot. The duration of exposure varies from 2 to 14days in an ambient temperature ranging from +50° F. to +20° F.with a wet ground condition.

3. Immersion Foot. This condition is usually a sea-going injury.The duration of exposure ranges from 12 hours to 7 days with the involvedpart immersed in water which has a temperature ranging from +60° F.to +25° F.

The military history of this world cannot be written or discussed withoutencroaching on the problem of cold injury. The writings of Baron Larrey,Aristotle, Hippocrates, and even of Galen refer to cold injury as a militaryproblem. In every war since the American Revolution in 1775 cold injuryhas taken its toll. From 1775 to 1920, based on meager statistics, approximately143,863 men while in combat incurred a cold injury. Our own statisticsfor an 11-year period from 1942 to 1953 certainly point out the seriousnessof cold injury in military medicine. What has cold injury cost the AmericanArmy during World War II and Korea?



Average Hospital Days









3,022,385 x 12--$36,000,000 (app.)

*Presented 26 April 1954, to the Course on Recent Advancesin Medicine and Surgery, Army Medical Service Graduate School, Walter ReedArmy Medical Center, Washington,
D. C.


These figures represent a loss of an effective fighting force equalto approximately 14 divisions for a period of 60 days.

Prior to the Korean experience only one official medical directive,TB Med 81, dated 4 August 1944, pertaining to the prevention and managementof cold injuries existed. An excellent analysis and summary of World WarII cold injuries from the epidemiological and prevention viewpoint waspublished by Colonel Tom Whayne in 1950.

Colonel Whayne in his thesis pointed out the many gaps in our knowledgeof cold injury that need further study. He pointed out that instructionin cold injury prevention among the patients appeared to be inadequateand therefore was an important factor in the prevention. Data also showedthat physical, mental and emotional fatigue was more prevalent among thetrench foot casualties. Other factors that were thought to contribute toan increased incidence of cold injury were: previous cold injury, age,race and geographical origin, psychosocial factors and environmental factorssuch as temperature, wetnesss, wind and terrain.

In cold injury the agent cannot, unfortunately, be eradicated, for aslong as warfare is conducted in cold climates, low temperatures will alwaysbe operative. Again, the agent cannot be isolated unless the locale forsuch warfare is avoided. However, an attempt can be made to interfere withthe transmission of the agent by reducing heat loss in every conceivableway. This may be done by enhancing whatever factors contribute to thisresistance or reducing susceptibility by minimizing or abolishing thosefactors which increase the susceptibility of the host.

As previously mentioned, at the end of World War II certain pertinentproblems in cold injury remained unanswered. To mention a few, low temperatureas the agent had not been completely explored and quantitated in establishinga gradient of injury, nor had attempts at measuring predictability fromanticipated temperatures been successful. The relation of duration of exposureto temperature as an index to injury had not been delineated and the synergisticeffect of wetness had not been completely evaluated.

Similarly, factors modifying host resistance or susceptibility remainedto be quantitated and their interactions assessed. Among these are previouscold injury, nutrition, fatigue as a product of the intensity and durationof stress, training, race, geographic origin and possible acclimatization,inherent constitutional factors and such psychosocial factors as morale,motivation and intelligence.

The socio-economic aspects of environment also were not without theirunanswered or inadequately defined problems. The role of intensity of combatactivity remained an elusive quantitation as did shelter, clothing, footdiscipline, leadership and unit experience.


Thus the studies of the European Theater of Operations begged not onlyfor repetition in application to frostbite but also for extension in thehope of clarifying at least a few of the relationships. The Korean conflictthus became the field study laboratory in the epidemiological approachto cold injury, its prevention and treatment.

In the winter of 1950-51 a systematic attempt to analyze the multiplefactors contributing to mass frostbite in military operations was made.A standardized method for the clinical management of large groups of frostbitecasualties was proposed since no management program or procedures for theutilization of injured personnel existed prior to 1950. In the winter of1951-52 a more detailed study directed at quantitating and clarifying theroles of the many modifying factors in the prevention, treatment and subsequentutilization of cold-injured military personnel was undertaken. A comprehensivereview and statistical analysis of the studies conducted in the wintersof 1950-51 and 1951-52 in Korea has been published and is available uponrequest from the Medical Research and Development Board, Office of TheSurgeon General. Because of the short period of time assigned to this subject,only the highlights of the cold injuries can be presented, omitting muchof the important statistical proof which clarifies many heretofore unansweredfactors in cold injury.

Epidemiological Findings

The epidemiological study of the relationship of cold trauma to thecombat soldier in Korea during 1951-52 dealt with 1,044 cases of cold injury.Data on 716 cases of frostbite and their 455 "bunker mate" controlswere analyzed. In addition, selected data on 1,628 pre-exposure controlswere utilized.

Relatively higher linear correlations of frostbite incidence with dailyaverage temperature, daily minimum temperature and daily average windchillwere obtained. Separation of the data according to intensity of combatpermitted fairly reliable prediction formulae to be calculated. Thoughapplicable only to comparable situations, the method appears to hold promisefor future prediction calculations in other types of situations. The meanminimum temperature to which the casualties were exposed was +11° F.and the absolute lowest temperature was -11° F. The mean duration ofexposure of frostbitten patients was 10 hours, but varied with the specifictype of activity.

Although both casualties and their controls were exposed to similarenvironmental factors including specific "micro-activity" suchas immobilizing enemy action, the patients showed markedly less muscularmovement than did the controls. The absolute number of frostbite casesof the feet occurring in shoepacs was greater but calculations


equalizing exposure revealed that the leather boot was more conduciveto frostbite and more frequently caused greater severity of injury. Combattroops frequently failed to carry extra footwear for changing wheneverthe situation permitted. Of 252 casualties in situations permitting sockand insole change only 77 percent carried this extra footwear, whereasof 214 controls in similar situations 92 percent carried extra footwear.Inadequate insole change contributed significantly to frostbite incidenceof troops wearing shoepacs. A significant excess of casualties with frostbittenhands wore either no handgear or incomplete glove ensembles at time ofinjury.

A previous cold injury indicated a predisposition to frostbite. Theattack rate for soldiers not previously cold injured was 2.6 per 1,000compared to 5.0 per 1,000 for soldiers previously cold injured.

Collateral significant evidence was demonstrated which strengthenedthe impressions from the neuropsychiatric study that the frostbite patientstended to be passive, negativistic, hyponchondriacal individuals. Thisevidence included the factors of less muscular activity in situations permittinggreater activity, relative inattention to carrying extra footwear and lesssmoking.

The Negro was proven to be at greater risk of attack by frostbite (sixtimes) when all environmental factors were equalized. At regimental levelhis rate was 35.9 per 1,000 as compared to 5.8 per 1,000 for the whitesoldier. Negroes had more severe degrees of frostbite than did the whites.

The climatic region of origin of the soldier was shown to be a highlysignificant factor among white troops in the incidence of frostbite. Originfrom warmer climates of the United States (or Hawaii and Puerto Rico) indicateda predisposition to frostbite. With all environmental factors equalizedthe attack rate for the "Southern" soldier was 1.6 times greaterthan that for the "Northern" soldier. There was more evidencefor accustomization rather than acclimatization as an explanation for thisdifference.

Clinical Findings

The earliest effects of cold were not elucidated in our studies. Theprincipal reason for this was the delay of the patient in reaching a medicalinstallation after being injured. Therefore still lacking is the documentationof the gross tissue changes that take place immediately after rewarmingof the injured part and up to 24 hours after injury. Until this informationis obtained, recognition and proper classification of the injury remainsinconsistent. No knowledge was gained on the question of amelioration ofthe severity of the injury by means of therapy prior to 40 hours afterinjury. No lessening of the severity of the injury by therapy after thisinterval was noted.


The benefit of the routine management program in a special center forfrostbite as developed during the winter of 1950-51 and adhered to in thewinters of 1951-52 and 1952-53 is well documented. Strict compliance withthe program is a necessity which demands discipline of the doctors, nurses,corpsmen and patients.

The program is still hampered by the delay in institution of first aidmeasures immediately after injury. Traumatization or re-exposure to coldof the already injured part results in delayed healing. To prevent delayin institution of medical care better indoctrination of the infantrymen,aidmen and unit surgeons in recognition and management of frostbite isnecessary. Measures should be instituted to accomplish rewarming of cold-injuredparts by exposure to temperatures of 70° F. to 80° F. Rewarmingmeasures such as massage, exposure to an open fire or by walking shouldbe discouraged. No specific therapy was proven to be of benefit in promotingrapid healing of the frostbitten tissues or in decreasing the severityof the injury when treatment was instituted on an average of 40 hours afterinjury.

The last phase in the management of a frostbite casualty is his dispositionand future assignment in the military service. Because of the late changesproduced in the neural and vascular tissues by frostbite and the increasedsensitivity of the injured part to cold, the following recommendationsare made:

1. In confirmed cases of cold injury the soldier should be given a profileof L-3 or U-3 for a period of 5 years from time of injury.

2. Duty assignment of frostbite casualties should be governed by thefollowing factors:

    a. No preferential duty assignment will be necessary for localeswhere the mean minimum temperatures are above 25° F.

    b. The duty assignment must assure no prolonged outside exposurefor locales where the mean minimum temperatures are below 25° F.

    c. No personnel reprofiled because of frostbite should be assignedto locales where the mean minimum temperature is below 0° F.


Organization for a cold weather training program in Korea was institutedin August 1950. Determination of clothing requirements for the combat unitsand preparation of requisitions for the necessary winter clothing and equipmentwas started in September. Instruction teams were formed under the auspicesof the Quartermaster Corps. The mission of these teams was to instructall combat units of battalion size in the proper use of winter clothingand equipment, signs of cold injury, and some of the simple principlesof prevention; such as, shelter, physical activity, and the like.


Because of a fast-moving offensive action of the U. S. troops in Septemberand October 1950 followed by harassed retrograde movements in November,cold weather ensued before all troops had received cold weather training.Also in some instances units had not received their necessary cold weatherclothing and equipment. The net result of inadequate preparation for coldweather coupled with heavy combat can be found in the incidence of frostbitefor the winter of 1950-51.

The preparation for the 1951-52 cold weather program began in July 1951.All winter clothing and equipment was issued by 31 October 1951. Trainingteams under the direction of the Quartermaster Corps were utilized forthe training of unit instructors who in turn instructed all personnel oftheir respective organizations. The training responsibility was made partof the command responsibility. The training sessions for instructors werescheduled to cover a 2-day period and consisted principally in a discussionof the various types, signs, causes and possible effects of cold injuries.Training aids, including clothing demonstration sets, were also distributedto each unit instructor. Training of the unit teams was completed by October1951 and of the respective units by November 1951. In spite of light combatactivity, a milder winter and the introduction of better winter clothingincluding the new insulated rubber combat boot, the United States troopsduring the second winter sustained 716 cases of frostbite.

The training program for the third winter (1952-53) was almost identicalto that of the preceding winter. The combat activity of the third winterwas even less intense, the winter clothing was of better design and morewidely distributed, yet our troops incurred 322 cases of cold injury.

The Korean conflict has again proven that cold injury is a serious problemthat has not been solved, even in the time of modern warfare.

The most important principle in prevention of cold injury is the initiationof a training program well in advance of the cold season, even months oryears before cold trauma may be expected to affect troops. Top commandmust lay down an effective training policy, staff must effectuate thatpolicy. If the need for a preventive program is not convincingly presented,command may not understand the potential cost of cold trauma and may, therefore,be unwilling to undertake a costly and time-consuming preventive programin advance. A program in order to be effective must begin in the Zone ofInterior by the training and indoctrination of all line and staff officers,service officers and especially the noncommissioned officers and enlistedmen of replacement training centers in the technical aspects of cold traumaand its causative factors. Without this prior indoctrination of all ranksan effective program of prevention in the theater of war will not be forthcoming.In the theater just preceding cold weather


emphasis must be placed on repeating the field training which dealswith the practices of prevention.Supply of clothing and other equipment,unit policies and practices and repetitious training of the individualsoldier must be stressed.

Much has been written and published concerning the various preventivedevices pertaining to cold injury. Rather than to list all of the measurespreviously known or recommended it is desired to present only those factorsthat were found in our controlled epidemiological study to be exertinga profound influence on the incidence of injury

Weather consciousness is most essential in the prevention of cold injuries.Each unit (battalion and regiment) should take an active part in localweather observation and predictions so that its practical application tothe proper wearing of clothing and length of exposure within the limitsof military expediency may be realized. From the experience gained followingthe installation of 88 weather stations by the Cold Injury Research Teamin combat units in Korea during the winter of 1951-52, it is believed thatweather information and simple weather predictions can be applied in theplanning of tactical operations with regard to type of clothing to be worn,extra items of gear to be carried and fixing the duration of the givenmission. Too often in the past unit commanders have made decisions as totype of clothing to be worn, duration of the tactical mission, ect., withoutbeing aware of the climatic conditions present or expected. Tactical decisionsthat are made without a keen weather consciousness definitely increasethe incidence of cold injury.

Immobilization is a major factor contributing to cold injury. Troopsshould be impressed with the need for muscular movement to the fullestextent which the combat situation permits. Muscular activity can be carriedon even with the soldier pinned down by enemy fire, placed on interiorguard duty, assigned to an outpost guard position or placed in a motormovement. Aggressive troops do not sustain cold injuries.

The wearing of items of body clothing should be predicated upon theexisting or predicted weather conditions rather than on the basis of Army-widedirectives relating to seasons. Certain basic principles regarding thelayers of body clothing are frequently overlooked or neglected. This includesthe ventilation of the body during physical activity, cleanliness of clothingto prevent loss of insulation and the avoidance of constriction such asprovided by snug-fitting boots, underwear, sweaters, jackets and trousers.

Front-line units should be equipped with properly fitted new insulatedrubber boots for winter combat. Cognizance should, however, be taken ofthe several shortcomings of this boot. Even greater and more strict attentionmust be paid to foot hygiene while wearing the


boot. Neglect of foot hygiene for a few days will incapacitate the individualsoldier for combat duty.

Greater attention should be paid to proper bootgear-sockgear combinationsto avoid either inadequate insulation or constriction. Extra footwear shouldbe carried at all times so that the soldier may take advantage of any opportunityfor change and not be guided blindly by "daily change" directives.Many casualties state that they were ordered by their platoon leaders tostrip themselves of all extra gear prior to a particular combat activity.Consequently, many of the soldiers discarded their extra gear believingthat they were following the order issued by the platoon leader. Subsequently,during the ensuing combat operation wetting of the feet or hands resulted.Often during the operation these men were then positioned on an outpostguard or in ambush patrol where immobilization coupled with wet feet occurred.Such incidents usually resulted in a loss of manpower by frostbite. Dailyinspection of the feet by the squad leader to include boot and sockgearadequacy should be mandatory and unit commanders should require verbalreport of such inspections.

There are no provisions for the immediate replacement of handgear whichhas become wet, torn or lost during a tactical operation. In addition,the operation of certain weapons and the execution of many procedures duringa tactical operation using the presently prescribed handgear necessitatesremoval of this gear to perform the task. It is strongly recommended thatall soldiers undergo repeated supervised periods of practice in handlingtheir weapons while wearing the complete mitten ensemble. These practicesessions should be conducted by the squad and platoon leaders throughoutthe winter whenever the tactical situation permits.

Cold weather orientation and training should be started in all serviceschools and extended into the combat theater. Simple educational technicsof a public health nature may be employed to keep both the problem andits prevention before the troops at all times. Repetition is essential.A record of cold weather indoctrination and training should be enteredon all soldiers' DA Form 20 (Qualification Record-Enlisted Personnel) andthe officers' DA Form 66 (Officer Qualification Record).

The "special risk" groups (Negroes, white troops from Southernclimatic regions, previously cold-injured personnel, fatigued soldiers,and negativistic individuals) should be given greater attention in orientation,winter combat training, teaching of foot hygiene and in foot inspection.Unit commanders should recognize that, to retain these groups as effectiverifle power in the line, personal attention to preventive measures amongthem will be necessary.


Cold injury control officers with full freedom of investigation andreport should be stationed with each unit of battalion size or larger.These officers should, in addition to their indoctrinational duties intraining and orientation, advise on correction of irregularities of supplyand utilization of gear, and assist the unit commanders in their evaluationof weather conditions in the tactical operations.

Every opportunity for rest back of the line should be provided as battleactivity permits. Evidence exists that some soldiers did not avail themselvesof trips to shower points which afford an opportunity for brief rests.


A critical resumé of our knowledge and experiences in the preventionand treatment of cold injuries yields the following conclusions:

1. The Korean conflict again demonstrated the fact that United Statestroops are not capable of engaging in cold weather combat without incurringsignificant numbers of cold injury casualties. The record of the KoreanWar is no better than that of World Wars I and II.

2. The training of the soldier in cold weather combat is still not realistic.Training and indoctrination should be repetitious, starting during thebasic training period of the soldier and officer. The soldier must firstlearn how to cope with his environment before he can become a part of aneffective fighting unit. One example of the shortcomings in our trainingprogram is the familiarity of the soldier with the cold weather clothingand equipment. At Fort Knox in the years of 1950 through 1953 not a singleset of combat winter clothing was available for demonstration purposes.Time is too short in the combat theater to train the soldier and officerin the many protective and preventive devices relating to cold weatherwarfare. Our training program is entirely inadequate and poorly timed.

3. A selection of men for cold weather combat is possible. By excludingcertain easily identifiable men it is possible to form a special combatunit which during a cold weather operation will be resistant to the effectsof cold and will sustain a minimum of cold injury casualties.

4. Frequent and necessary rotation of troops out of the line for a briefrest period will materially reduce the incidence of cold injuries. Operationalplanning should provide sufficient number of troops so that rotation ispossible.

5. An increasing awareness by the individual soldier and the commandwith respect to the climatic potentialities will lead to the applicationof more effective preventive measures. Cold injury control officers assignedto combat units can be the motivating force in increasing weather consciousnessamong the troops.


6. The treatment and management program for cold injuries is now wellstandardized and effective. The average number of hospital days has beenreduced from 50 to 28. The utilization of previously cold-injured personnelis realistic and saving of manpower.

In closing, it can be stated that the measures for prevention and managementof cold injuries are well documented. Still lacking is the practical applicationof our knowledge into our training programs, which up to date have beeninstituted too late and in too scanty a manner to be effective.