Table of Contents
After reading this article, be sure to visit our Trauma section
to see our Frostbite Pictures.
Frostbite is defined as the body’s inability to compensate
for cold exposure, that produces injury. A decrease in temperature
is not the only factor that causes frostbite. Time of exposure,
humidity, wind, clothing, a past history of certain medical
conditions, and behavior may all be contributing factors.
Ethnic origin may be another; for example, individuals who
have for generations made their homes in a temperate climates
as opposed to individuals from colder environmental regions
such as Alaska, who are acclimatized to the cold.
It has been well documented throughout history that frostbite
(especially in times of war) has consistently contributed
to increased mortality and morbidity. During the year 1812-1813,
Napoleon’s army lost many soldiers to frostbite. He
left France with 250,000 men, returning approximately 6 months
later with only 350 fully functioning soldiers. Of course
part of this was due to Napoleon’s own arrogance.
During WWII, the Germans performed approximately 15,000 cold-related
Until the 1950’s frostbite treatment consisted of rubbing
snow over the affected area. However in 1956, Merryman disproved
this treatment intervention. He instead encouraged the public
health service medical officer in Tanana, Alaska to try rapid
re-warming, with great success--Hence, the beginning of a
new and effective treatment for frostbite.
The physiology of frostbite consists of several phases.
In the first phase of frostbite, the skin temperature begins
to drop, and blood flow to the surface of the skin dramatically
decreases. As the cooling process begins, the body initiates
the Hunting response, a 5-10 minute cycle where the blood
vessels dilate, and then contract, which is the body’s
attempt to re-warm. Hunting response is more frequently seen
in populations native to cold environments such as Eskimo’s,
where the response is far stronger. The medical term used
for the Hunting response is cold-induced vaso-dilation. The
first phase is defined as a pre-freeze phase.
The second phase is considered a freeze-thaw phase. It is
between the freeze-thaw phase and the vascular stasis or third
phase that we see intracellular fluid shifting across cell
membranes. Theoretically it is thought that this is the phase
where actual ice crystal formation occurs.
The next phase, the late ischemic phase, is the most severe.
During this phase, the skin becomes necrotic and gangrenous.
There can actually be bone involvement during this phase.
It is important to note phases can, and often do, overlap.
Frostbite can be classified in different degrees or stages,
much like burns. 1st degree frostbite shows partial skin redness
(erythema), swelling, usually no blisters. Symptoms include
burning or throbbing pain. Stinging is sometimes reported
by some patients. 2nd degree is redness. Sometimes vesicles
and blisters are seen. These blisters can form a blackened
area on the skin. Numbness is a symptom often seen. 3rd degree
burns are much deeper, where there is full-thickness freezing
of the skin, with hemorrhagic blisters. There can be some
skin death. Symptoms include feeling of no sensation, burning,
throbbing and aching (please see frostbite picture on Survive
Outdoors, emergency photo section, for 3rd degree frostbite).
4th degree frostbite is the most severe state. It is usually
full-thickness, involving muscle, tendons and bones. There
is minimal swelling. At this point, these look very mummified.
Pain at the joints is a possible symptom. This system of classification
has received widespread use, especially by emergency rooms.
Outdoor Treatment for Frostbite
Outdoor treatment is relatively simple.
All wet clothing should be removed, replaced by dry clothing,
if available. Wrapping the areas in sterile gauze, if available,
would be highly beneficial. However if not available, wrapping
in any dry material is advised. Elevate the frostbitten area.
Rapid re-warming has proven to be the most important treatment
modality. However, there is some controversy surrounding the
re-warming process. Some authors believe re-warming should
occur only after being transported out to an ED (emergency
department). Others suggest that rapid re-warming should occur
in the field, running the risk of possibly refreezing the
affected body part. This author has found few studies comparing
the pros and cons of these options, improved outcome vs. morbidity
in the case of refreezing. If an affected individual is 4-5
days from being transported out, this author believes waiting
until arrival in the ED before re-warming is the safest and
Other outdoor treatment should be placing
cotton or cut up pieces of clothing between the toes or fingers.
DO NOT DEBRIDE BLISTERS, as you will increase risk of infection.
When considering re-warming in the outdoors,
many individuals think of warming water over a fire and using
a thermometer to gauge the temperature. Of course this is
rather ridiculous, as most individuals do not carry a thermometer
with them in the outdoors. Subsequently, a nice rule of thumb
is as follows: Water should be warmed to approximately 104
degrees Fahrenheit. This is the water that should be used
to rapidly re-warm. This temperature is about that of a hot
tub. After warming the water, if you place your hand in the
water and immediately have to take it out, it is clearly above
104 degrees. At 104 degrees, one can leave their hand in the
water for an extended period of time without feeling pain.
AT THE RISK OF BEING REDUNDANT, ONLY CONCERNED,
REMEMBER: DO NOT RUB SNOW ON ANY FROSTBITTEN AREA.
You can treat with nonsteroidal anti-inflammatories
such as Ibuprofen, which also helps with anti-prostaglandin
Healthcare provider – Medical
Rapid re-warming in the ED or urgent
care center can be used with a small whirlpool, warming the
water to about 104-105 degrees Fahrenheit. Here, now, the
temperature can be exact as a thermometer will be available.
The frostbitten region should be warmed for approximately
15-30 minutes, until the very distal aspect of the extremity
is pliable. Blisters should be debrided. Silvadene can be
applied; however, a word of caution. For hemorrhagic blisters,
treatment is still controversial in the ED, as well as the
use of prophylactic antibiotics.
Tetanus immunization update should be stressed.
The majority of research is pointing to treatment of blisters
with an Aloe Vera cream every 6 hours. Also there have been
good outcomes with a tapered dose of oral Prednisone. Close
follow-up is essential, and the administration of Ibuprofen,
600-mg. every 12-hours.
Dr. Auerback goes on to discuss hydrotherapy
daily for 30-40 minutes. At discharge, it is very important
to explain to patients that they are going to be more successful
in avoiding frostbite in the future if they pay attention
to preventing a recurrence, such as wearing proper clothing
in the outdoors.
Be aware of what the anticipated weather
is on your trip. Try to look at long-range forecasts. Dry
clothing is extremely important. A waterproof bag containing
an extra set of clothes and socks is imperative. Please see
the section on Survive Outdoors on staying warm in the outdoors,
and the importance of layering. Always have some type of headgear,
since the vast majority of heat is lost through your head
and neck. It is important to be in good physical shape. If
you are a smoker, stop smoking, or decrease smoking for the
trip. It has been shown that even if you stop for one day,
or decrease your smoking during a trip, this definitely plays
a role in somewhat decreasing your risk for frostbite. Proper
hydration and good food intake is very important. Use of pocket
heaters or foot warmers is advised. They are easy to find,
inexpensive, and very effective. Putting your hands under
your armpits or in the groin region can be effective. In emergent
situation, you can even place your feet into your partner’s
armpits. This is not a time for social formality; it is the
time to be concerned about your partner’s health. This
is also very effective in warming. Do not blow on somebody’s
toes. Many times this author in hunting scenarios has seen
individuals cup their hands over someone’s toes and
blow on them. This is not usually effective or warranted.
When you blow, you run the risk of getting small amounts of
saliva, as well as increasing humidity to the area, and this
will only exacerbate the situation. Windmilling is very effective.
It is literally taking one’s arms and spinning them
around in a clockwise or counterclockwise fashion as fast
as possible. This will vaso-dilate the hands and fingers,
and help increase blood flow. Although transient, it definitely
does help, and can be repeated. Avoid tight-fitting clothes,
especially on the hands and feet. Mittens are clearly much
warmer than gloves. Be careful of metallic objects when grabbing
or holding them in extremely cold weather. Gun barrels, cameras,
and shovels especially when hands are moist can be very dangerous.
Please refer to the movie A Christmas Story and the little
boy who was coaxed into putting his tongue on the flagpole.
There is much evidence to support not washing
your skin thoroughly, or not washing at all for 3-4 days,
as a way to protect against frostbite. This has been shown
in studies of Nordic fishermen (who are also acclimatized
to a greater degree). Individuals are more susceptible to
frostbite when having cleaner skin.
Tetanus should be updated before travel.
When going into the outdoors, in any situation, common sense
is a must. Again, be advised—if you have ever had a
frostbite injury, you will be at much greater risk down the
1. Judith Tintanelli, Emergency
Medicine: A Comprehensive Study Guide
2. Paul S. Auerbach, Wilderness
Medicine, 4th Edition.
and Cold Injury, an Update.
Donner, M.D., Howard.