Page 125 - 2020 JSOM Winter

An Ongoing Series

Frostbite

Pathophysiology, Epidemiology, Diagnosis, Treatment, and Prevention

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Joseph J. Knapik, ScD *; Katy L. Reynolds, MD ; John W. Castellani, PhD 3
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ABSTRACT
Frostbite can occur during cold-weather operations when the Introduction
temperature is <0°C (<32°F). When skin temperature is ≤–4°C Historians have documented the adverse effects of cold weather
(≤25°F), ice crystals form in the blood, causing mechanical on military operations since the beginning of recorded history.
damage, inflammation, thrombosis, and cellular death. Lower In 401/400 BCE, Xenophon marched 10,000 retreating Greek
temperatures, higher wind speeds, and moisture exacerbate soldiers across the Armenian mountains, and only about 4,000
the process. The frozen part or area should not be rewarmed survived. Most were lost to exposure and frostbite. Hannibal
unless the patient can remain in a warm environment; repeated crossed the Alps in October 218 BCE with plans to conquer
freeze/thaw cycles cause further injury. Treatment involves Rome. He lost 28,000 of 47,000 men, largely because of the
rapid rewarming in a warm, circulating water bath 37°C to cold and mountain tribes who opposed him. During Napo-

39°C(99°F–102°F) or, if this is not possible, then contact with leon’s retreat from Moscow in 1812, temperatures fell to near
another human body. Thrombolytics show promise in the –40°C (–40°F). The retreat started with about 110,000 sol-
early treatment of frostbite. In the field, the depth and severity diers, but by the time the Army arrived in Poland, only 10,000
of the injury can be determined with laser Doppler ultrasound effective soldiers remained. During the American Civil War
devices or thermography. In hospital settings, bone scintig- (1861–1865), there were an estimated 15,000 injuries result-
raphy with single-photon emission computed tomography ing from the cold. Amputations were common, many for frost-
(SPECT) 2 to 4 days postinjury provides detailed information bite. In the first few months of WWI, the British Army suffered
on the depth of the injury. Prevention is focused primarily on 9,000 cases of what medical personnel recorded as “frostbite.”
covering exposed skin with proper clothing and minimizing On the WWI eastern front, Russians reported that 8% of all
exposure to wind and moisture. The Generation III Extended casualties were the result of cold, and the Germans reported
Cold Weather Clothing System is an interchangeable 12-piece 10,000 frostbite cases in a single night. In WWII, it was esti-
clothing ensemble designed for low temperatures and is com- mated that lost man-days resulting from cold injury was equiv-
patible with other military systems. The Extreme Cold Vapor alent to 7,579 lost man-years, or an entire division (i.e., 10,000
Barrier Boot has outer and inner layers composed of seamless to 15,000 Soldiers) out of action for 6 months. In 1944/1945,
rubber with wool insulation between, rated for low tempera- cold injury losses among riflemen were equivalent to the lost
tures. The Generation 3 Modular Glove System consists of 11 fighting strength of 12 divisions. During the Soviet invasion of
different gloves and mitts with design features that assist in Finland in early WWII, 7% of injured Russian troops and 12%
enhancing grip, aid in the use of mobile devices, and allow of injured Finnish troops suffered frostbite. In the Korean War
shooting firearms. Besides clothing, physical activity also in- battle at Chosin Reservoir, US Marines fought Chinese Com-
creases body heat, reducing the risk of frostbite.
munist troops. Among the Marines were 2,700 nonbattle casu-
alties, of which 2,000 (74%) were frostbite cases. There are
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Keywords: temperature; wind; moisture; thrombolytics; laser documented cases in which frostbite has hampered operations
Doppler ultrasound; bone scintigraphy; computed tomog- or resulted in mission failure among Special Forces soldiers. 4,5
raphy; Extended Cold Weather Clothing System; Extreme
Cold Vapor Barrier Boot; Generation 3 Modular Glove Sys- The cases of serious cold-related injuries have decreased in
tem; physical activity
more recent years largely because of a better understanding
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of physiologic responses to cold weather, the development of
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*Correspondence to joseph.j.knapik.ctr@mail.mil
1 MAJ (Ret) Knapik is a senior epidemiologist/research physiologist with the Henry M. Jackson Foundation for the Advancement of Military
Medicine, Bethesda, MD, and an adjunct professor at Uniformed Services University of the Health Sciences, Bethesda, MD, and Bond University,
Robina, Gold Coast, Queensland, Australia. COL (Ret) Reynolds volunteers as a primary care sports medicine physician in the Department of
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Defense medical facilities. Dr Castellani is a research physiologist in the Thermal and Mountain Medicine Division at the U.S. Army Research
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Institute of Environmental Medicine, Natick, MA.
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