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Chapter 1, Part 6

Medical Science Publication No. 4, Volume II



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

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

2. Trench Foot. The duration of exposure varies from 2 to 14 days 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 involved part 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 without encroaching on the problem of cold injury. The writings of Baron Larrey, Aristotle, Hippocrates, and even of Galen refer to cold injury as a military problem. In every war since the American Revolution in 1775 cold injury has taken its toll. From 1775 to 1920, based on meager statistics, approximately 143,863 men while in combat incurred a cold injury. Our own statistics for an 11-year period from 1942 to 1953 certainly point out the seriousness of cold injury in military medicine. What has cold injury cost the American Army 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 Advances in Medicine and Surgery, Army Medical Service Graduate School, Walter Reed Army Medical Center, Washington,
D. C.


These figures represent a loss of an effective fighting force equal to 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 management of cold injuries existed. An excellent analysis and summary of World War II cold injuries from the epidemiological and prevention viewpoint was published by Colonel Tom Whayne in 1950.

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

In cold injury the agent cannot, unfortunately, be eradicated, for as long as warfare is conducted in cold climates, low temperatures will always be operative. Again, the agent cannot be isolated unless the locale for such warfare is avoided. However, an attempt can be made to interfere with the transmission of the agent by reducing heat loss in every conceivable way. This may be done by enhancing whatever factors contribute to this resistance or reducing susceptibility by minimizing or abolishing those factors which increase the susceptibility of the host.

As previously mentioned, at the end of World War II certain pertinent problems in cold injury remained unanswered. To mention a few, low temperature as the agent had not been completely explored and quantitated in establishing a gradient of injury, nor had attempts at measuring predictability from anticipated temperatures been successful. The relation of duration of exposure to temperature as an index to injury had not been delineated and the synergistic effect of wetness had not been completely evaluated.

Similarly, factors modifying host resistance or susceptibility remained to be quantitated and their interactions assessed. Among these are previous cold injury, nutrition, fatigue as a product of the intensity and duration of 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 their unanswered or inadequately defined problems. The role of intensity of combat activity remained an elusive quantitation as did shelter, clothing, foot discipline, leadership and unit experience.


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

In the winter of 1950-51 a systematic attempt to analyze the multiple factors contributing to mass frostbite in military operations was made. A standardized method for the clinical management of large groups of frostbite casualties was proposed since no management program or procedures for the utilization of injured personnel existed prior to 1950. In the winter of 1951-52 a more detailed study directed at quantitating and clarifying the roles of the many modifying factors in the prevention, treatment and subsequent utilization of cold-injured military personnel was undertaken. A comprehensive review and statistical analysis of the studies conducted in the winters of 1950-51 and 1951-52 in Korea has been published and is available upon request from the Medical Research and Development Board, Office of The Surgeon General. Because of the short period of time assigned to this subject, only the highlights of the cold injuries can be presented, omitting much of the important statistical proof which clarifies many heretofore unanswered factors in cold injury.

Epidemiological Findings

The epidemiological study of the relationship of cold trauma to the combat 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" controls were analyzed. In addition, selected data on 1,628 pre-exposure controls were utilized.

Relatively higher linear correlations of frostbite incidence with daily average temperature, daily minimum temperature and daily average windchill were obtained. Separation of the data according to intensity of combat permitted fairly reliable prediction formulae to be calculated. Though applicable only to comparable situations, the method appears to hold promise for future prediction calculations in other types of situations. The mean minimum temperature to which the casualties were exposed was +11° F. and the absolute lowest temperature was -11° F. The mean duration of exposure of frostbitten patients was 10 hours, but varied with the specific type of activity.

Although both casualties and their controls were exposed to similar environmental factors including specific "micro-activity" such as immobilizing enemy action, the patients showed markedly less muscular movement than did the controls. The absolute number of frostbite cases of the feet occurring in shoepacs was greater but calculations


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

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

Collateral significant evidence was demonstrated which strengthened the impressions from the neuropsychiatric study that the frostbite patients tended to be passive, negativistic, hyponchondriacal individuals. This evidence included the factors of less muscular activity in situations permitting greater activity, relative inattention to carrying extra footwear and less smoking.

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

The climatic region of origin of the soldier was shown to be a highly significant factor among white troops in the incidence of frostbite. Origin from warmer climates of the United States (or Hawaii and Puerto Rico) indicated a predisposition to frostbite. With all environmental factors equalized the attack rate for the "Southern" soldier was 1.6 times greater than that for the "Northern" soldier. There was more evidence for accustomization rather than acclimatization as an explanation for this difference.

Clinical Findings

The earliest effects of cold were not elucidated in our studies. The principal reason for this was the delay of the patient in reaching a medical installation after being injured. Therefore still lacking is the documentation of the gross tissue changes that take place immediately after rewarming of the injured part and up to 24 hours after injury. Until this information is obtained, recognition and proper classification of the injury remains inconsistent. No knowledge was gained on the question of amelioration of the severity of the injury by means of therapy prior to 40 hours after injury. No lessening of the severity of the injury by therapy after this interval was noted.


The benefit of the routine management program in a special center for frostbite as developed during the winter of 1950-51 and adhered to in the winters of 1951-52 and 1952-53 is well documented. Strict compliance with the 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 aid measures immediately after injury. Traumatization or re-exposure to cold of the already injured part results in delayed healing. To prevent delay in institution of medical care better indoctrination of the infantrymen, aidmen and unit surgeons in recognition and management of frostbite is necessary. Measures should be instituted to accomplish rewarming of cold-injured parts by exposure to temperatures of 70° F. to 80° F. Rewarming measures such as massage, exposure to an open fire or by walking should be discouraged. No specific therapy was proven to be of benefit in promoting rapid healing of the frostbitten tissues or in decreasing the severity of the injury when treatment was instituted on an average of 40 hours after injury.

The last phase in the management of a frostbite casualty is his disposition and future assignment in the military service. Because of the late changes produced in the neural and vascular tissues by frostbite and the increased sensitivity of the injured part to cold, the following recommendations are made:

1. In confirmed cases of cold injury the soldier should be given a profile of 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 the following factors:

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

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

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


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


Because of a fast-moving offensive action of the U. S. troops in September and 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 weather clothing and equipment. The net result of inadequate preparation for cold weather coupled with heavy combat can be found in the incidence of frostbite for 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. Training teams under the direction of the Quartermaster Corps were utilized for the training of unit instructors who in turn instructed all personnel of their respective organizations. The training responsibility was made part of the command responsibility. The training sessions for instructors were scheduled to cover a 2-day period and consisted principally in a discussion of the various types, signs, causes and possible effects of cold injuries. Training aids, including clothing demonstration sets, were also distributed to each unit instructor. Training of the unit teams was completed by October 1951 and of the respective units by November 1951. In spite of light combat activity, a milder winter and the introduction of better winter clothing including the new insulated rubber combat boot, the United States troops during the second winter sustained 716 cases of frostbite.

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

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

The most important principle in prevention of cold injury is the initiation of a training program well in advance of the cold season, even months or years before cold trauma may be expected to affect troops. Top command must lay down an effective training policy, staff must effectuate that policy. 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 program in advance. A program in order to be effective must begin in the Zone of Interior by the training and indoctrination of all line and staff officers, service officers and especially the noncommissioned officers and enlisted men of replacement training centers in the technical aspects of cold trauma and its causative factors. Without this prior indoctrination of all ranks an 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 deals with the practices of prevention.Supply of clothing and other equipment, unit policies and practices and repetitious training of the individual soldier must be stressed.

Much has been written and published concerning the various preventive devices pertaining to cold injury. Rather than to list all of the measures previously known or recommended it is desired to present only those factors that were found in our controlled epidemiological study to be exerting a 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 local weather observation and predictions so that its practical application to the proper wearing of clothing and length of exposure within the limits of military expediency may be realized. From the experience gained following the installation of 88 weather stations by the Cold Injury Research Team in combat units in Korea during the winter of 1951-52, it is believed that weather information and simple weather predictions can be applied in the planning 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 given mission. Too often in the past unit commanders have made decisions as to type of clothing to be worn, duration of the tactical mission, ect., without being aware of the climatic conditions present or expected. Tactical decisions that are made without a keen weather consciousness definitely increase the incidence of cold injury.

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

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

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


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

Greater attention should be paid to proper bootgear-sockgear combinations to avoid either inadequate insulation or constriction. Extra footwear should be carried at all times so that the soldier may take advantage of any opportunity for change and not be guided blindly by "daily change" directives. Many casualties state that they were ordered by their platoon leaders to strip themselves of all extra gear prior to a particular combat activity. Consequently, many of the soldiers discarded their extra gear believing that 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 outpost guard or in ambush patrol where immobilization coupled with wet feet occurred. Such incidents usually resulted in a loss of manpower by frostbite. Daily inspection of the feet by the squad leader to include boot and sockgear adequacy should be mandatory and unit commanders should require verbal report of such inspections.

There are no provisions for the immediate replacement of handgear which has become wet, torn or lost during a tactical operation. In addition, the operation of certain weapons and the execution of many procedures during a tactical operation using the presently prescribed handgear necessitates removal of this gear to perform the task. It is strongly recommended that all soldiers undergo repeated supervised periods of practice in handling their weapons while wearing the complete mitten ensemble. These practice sessions should be conducted by the squad and platoon leaders throughout the winter whenever the tactical situation permits.

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

The "special risk" groups (Negroes, white troops from Southern climatic 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 effective rifle power in the line, personal attention to preventive measures among them will be necessary.


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

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


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

1. The Korean conflict again demonstrated the fact that United States troops are not capable of engaging in cold weather combat without incurring significant numbers of cold injury casualties. The record of the Korean War 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 the basic training period of the soldier and officer. The soldier must first learn how to cope with his environment before he can become a part of an effective fighting unit. One example of the shortcomings in our training program is the familiarity of the soldier with the cold weather clothing and equipment. At Fort Knox in the years of 1950 through 1953 not a single set of combat winter clothing was available for demonstration purposes. Time is too short in the combat theater to train the soldier and officer in the many protective and preventive devices relating to cold weather warfare. Our training program is entirely inadequate and poorly timed.

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

4. Frequent and necessary rotation of troops out of the line for a brief rest period will materially reduce the incidence of cold injuries. Operational planning should provide sufficient number of troops so that rotation is possible.

5. An increasing awareness by the individual soldier and the command with respect to the climatic potentialities will lead to the application of more effective preventive measures. Cold injury control officers assigned to combat units can be the motivating force in increasing weather consciousness among the troops.


6. The treatment and management program for cold injuries is now well standardized and effective. The average number of hospital days has been reduced from 50 to 28. The utilization of previously cold-injured personnel is realistic and saving of manpower.

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