7. FIELD SAFETY
7.1. TRAUMATIC
DISORDERS
7.1.1.
Avalanches
7.2. COLD INJURIES
7.2.1.
Hypothermia
7.2.2.
Frostbite
7.3.
HIGH-ALTITUDE SICKNESS
7.4. SAFETY
TRAINING
7.5. MEDICAL
FACILITIES
7. FIELD SAFETY
The importance of field safety considerations for this field experiment cannot be overstated. The field experiment will be conducted in remote, high mountain environments during late winter and early spring (which is still effectively winter in this environment). The measurement objective involves snow, which is a) cold, and b) often wet, which tends to make observers cold and wet if they are ill-prepared. Mountain storms can strike rapidly with little or no warning, changing conditions from fair and warm to white-out in a matter of minutes. Snow avalanches kill experienced backcountry travelers every year. Under clear, sunny skies, observers working on high-albedo snow fields can develop acute sunburn very quickly, in places they may not have previously considered eligible. Awareness of common injuries and medical problems in cold regions, and their symptoms, is important for all field personnel participating in this experiment.
Safety measures are an essential part of the risk reduction
strategy for the experiment. These include the team-oriented approach that
will be used for all data collection, and measures to provide strong navigation
and communication during the experiment (see Section 8). Also, field participants
will be required to attend a winter safety training course prior to the
first IOP each year.
Traumatic disorders - injuries produced by physical forces
such as falls or falling objects - are the most common in short mountaineering
trips. Observers traveling on skis or snowshoes may take an unusually hard
fall sufficient to require medical attention, or sustain other common injuries.
Observers traveling by snowmobile are prone to a larger variety of injuries
which can result from being thrown from the snowmobile, overturning, collisions,
etc. Snowmobile accidents involving low unseen tree branches, or more severely,
barbed-wire fences, are not uncommon. Helmets are an obvious and absolute
requirement for all snowmobile users during the field campaign.
Snow avalanches are common in many parts of the study
area. Most avalanche victims die from traumatic injuries sustained from
large blocks of snow or ice, or impact with rocks or trees, or from suffocation
under loose snow. The two requirements for avalanches - snow and gravity
- exist throughout the study area and can pose a significant hazard even
in seemingly unlikely areas. Many avalanche accidents occur on obvious,
reoccurring avalanche paths, but many also occur on modest slopes. Physiographic
characteristics and snow characteristics conducive to avalanches must both
be readily recognized by field observers to avoid accidents. General backcountry
avalanche warnings will be monitored closely during the experiment. At
least one member of each field party will be well-trained in avalanche
safety, and all field observers will receive basic training on avalanche
safety, what to do if caught in an avalanche, and avalanche rescue operations.
The most common major injuries produced by cold are hypothermia
and frostbite. Field observers working in winter, mountain conditions without
adequate preparations and safeguards are especially susceptible to these
injuries. All field personnel will be provided with lists of appropriate
clothing and gear to be carried in the field, and will receive basic training
to avoid cold injuries.
Hypothermia is a decrease in the core temperature of entire body which becomes significant when muscular and cerebral functions are impaired. Prevention of hypothermia is of utmost importance, and requires adequate amounts of water, food, and clothing. Hypothermia can advance rapidly, and can become life-threatening if not treated quickly. Every field observer should be trained to recognize signs of hypothermia. Mild hypothermia is most often accompanied by a feeling of chilliness. As the condition advances, the victim begins to lose muscular coordination; first fine hand movement is lost, then stumbling may occur. Shivering usually appears when body temperature has dropped two to four degrees. The intellect is also impaired as hypothermia develops. A common early sign is refusal to admit that anything is wrong. Subsequently the victim becomes apathetic and is unconcerned about his deteriorating condition. Mental sluggishness may be manifested by slow thought and speech. Signs of severe hypothermia usually occur when body temperature has fallen to about 90° F. An easily recognizable indicator of severe hypothermia is the gradual disappearance of shivering. Muscular incoordination is severe, and intellectual impairment is greater. A common and important sign of severe hypothermia is neglect or carelessness about protection from the cold. Eventually confusion and irrationality progress to incoherence and semiconsciousness. Finally, the victim loses consciousness entirely and become totally comatose.
Recognition of mild hypothermia is the most critical aspect
of its treatment. Treatment of mild cases involves decreasing heat loss
and increasing heat production, through a variety of means. Treatment of
severe hypothermia is a much more complex problem that is largely unresponsive
to treatments for milder cases. Rapid rewarming is hazardous and requires
great care. Medical facilities are equipped to perform such treatment safely,
but safely rewarming severely hypothermic cases in the field is difficult,
and most often is hopeless without evacuation. Seemingly insignificant
bumps and jolts caused by the evacuation itself can lead to fibrillation,
further complicating the problem. The key is to avoid hypothermia in the
first place.
Frostbite is an injury, usually localized, characterized by freezing of the tissues. The hands and feet, which are furthest from the heart and have a more tenuous blood supply, and the face and ears, which are often exposed, are most commonly affected. To conserve heat for the central portions of the body, blood vessels in the extremities constrict. Constriction can be so severe that circulation to those areas almost ceases. Cold also damages the capillaries in the affected areas, causing plasma to leak through their walls. As the circulation becomes so severely impaired, the skin and superficial tissues exposed to severe cold begin to freeze. With continued cooling, the frozen area enlarges and extends to deeper levels. Ice crystals form within and between the cells and grow by extracting water from the cells. The cells are injured physically by the ice crystals, as well as by dehydration and the resulting disruption of osmotic and chemical balance.
The typical early signs of frostbite are sensations of cold or pain and pallor of the affected skin. However, some victims may suffer little pain, and pain typically disappears as tissues begin to freeze. As freezing progresses, the tissues usually become even whiter in appearance and all sensation is lost. Severe frostbite can affect an entire hand or foot and lower leg. Frostbite of the face, tip of nose, or ears can be recognized by pain and pallor of the affected tissues. With minor frostbite the tissues may only be red for a few days after thawing. With more severe injuries, blisters commonly develop after rewarming and may cover entire fingers or toes. The most severe frostbite injuries are not followed by blisters; they are followed by spontaneous separation of the dead tissue.
Frostbite is best prevented by avoiding the conditions
by which it is produced. Proper clothing, and correctly fitting boots are
important for avoiding frostbite. Field observers must have a good understanding
of proper clothing for winter field work. The preferred treatment for frostbite
is rapid rewarming in a relatively large water bath, preferably administered
in a hospital. Rewarming in the field should only be attempted when evacuation
is not possible.
Medical problems associated with high altitude include a number of uncomfortable symptoms and some life threatening conditions. All are primarily the result of a decreased oxygen concentration in the blood caused by the lower atmospheric pressure at high altitude. The field experiment will be conducted at altitudes ranging from 8,000 to 14,000 feet. Eight thousand feet is a rough threshold above which altitude illness occurs.
Acute mountain sickness refers to a group of unpleasant
symptoms related to high altitude, including headache, dizziness, fatigue,
shortness of breath, loss of appetite, nausea and vomiting, disturbed sleep,
and a general feeling of unwell, comparable to "flu" or a hangover. Drowsiness
is common. After rapid ascents from sea level to between 8,000 and 10,000
feet occasional individuals have symptoms, and in some cases these can
be severe. High altitude pulmonary edema is the most dangerous of the common
types of altitude illness. This disorder results in a drop in the concentration
of oxygen in the blood, eventually causing cyanosis, impaired cerebral
function, and finally death by suffocation. The chances of developing symptomatic
high altitude pulmonary edema after a rapid ascent to 12,000 feet are about
one in two hundred. Symptoms include an undue shortness of breath, a sense
of "tightness in the chest", or a feeling of impending suffocation at night,
weakness, and marked fatigue. Relief from acute mountain sickness can usually
be achieved by descent to lower altitude, although in minor cases this
is not usually necessary. Recognition of symptoms of acute mountain sickness,
and an understanding of basic treatment, are important skills that must
be possessed by all field observers.
Many participants in the field experiment will likely
have substantial winter backcountry experience, but many likely will not.
Formal winter backcountry safety training will be provided for all field
personnel, regardless of experience, prior to the first IOP each year.
The safety training will be provided by recognized experts on the topic,
and will be given at the study site.
Emergent and non-emergent care facilities are available
in most larger towns throughout the study area, although ground transport
from remote field sites to such facilities can require several hours. Helicopter
evacuation is possible from the largest medical facilities in the area.