Temperature
Induced Stress - Cold Exposure
Part
1 of 2
T.R.
Consulting, Inc.
January
2003 Safety Article
Written
and compiled by:
Tony
Rieck
T.R.
Consulting, Inc. regularly publishes safety and environmentally related
articles on our website at http://www.trconsultinggroup.com/safety/archive.html.
These articles are a free service provided by T.R. Consulting, Inc. to all
interested parties in order to promote safety and environmental awareness. T.R. Consulting, Inc. also provides safety
training information and services.
Information about our safety training programs can be accessed at http://www.trconsultinggroup.com/safety/.
This
month’s article is the first of a two part series discussing temperature
induced stress. To access the second
part of this series about heat stress, go to http://www.trconsultinggroup.com/safety/feb2003.html.
Cold Exposure
Exposure
to very cold temperatures for extended periods of time can lead to either (or
both) frostbite or hypothermia.
Frostbite is tissue damage that develops in varying degrees depending
upon the duration of the skin exposure, the temperature of exposure and the
ratio of skin surface area to mass of the exposed skin. Hypothermia results when the body core
temperature falls below 95 degrees Fahrenheit.
Frostbite can be a severe injury depending upon the degree of frostbite
encountered. Hypothermia should be
considered a medical emergency and anyone suspected of suffering from it should
get medical attention as soon as possible.
Frostbite
Exposure
to temperatures below 32 degrees Fahrenheit can cause frostbite. Several degrees of severity are associated
with the resultant tissue damage.
Incipient frostbite (also termed as “frost nip”) is the mildest form of
frostbite. Incipient frostbite affects
only the tissue at or near the surface of the skin. Progressively, frostbite works its way deeper into the skin. So long as the frostbite does not affect the
blood vessels, recovery is generally complete.
In the case of deep frostbite affecting the blood vessels, glucose and
oxygen transport to the affected region discontinue and cell death
results. Cell death can lead to
gangrene, which can necessitate the amputation of the affected tissue or even
an extremity. In all cases, deep
frostbite causes permanent damage.
Any
part of the body can be affected by frostbite, but the areas of the body with
the highest ratio of surface area to mass are the most susceptible. These most susceptible areas are the ears,
the nose, the fingers and the toes.
Proper covering of the skin will prevent frostbite. Constriction of the blood flow to the
extremities can cause greater susceptibility to frostbite. Items that can cause constriction of blood
flow include rings, watches and tight fitting shoes (especially when wearing
several layers or thick socks).
Several
environmental factors can increase the susceptibility to frostbite as
well. Frostbite progresses more rapidly
at lower temperatures. The greater the
velocity of the wind (wind chill), the more quickly heat is removed from exposed
regions of skin. Finally, snow coming
in contact with exposed skin will initially turn to water. This formation of water on exposed skin can
leach heat from the skin and increase the rate of tissue damage.
Symptoms of Exposure
The
earliest sign of frostbite is a sensation of pins and needles, followed by
numbness and eventually complete numbness.
The skin appears white and feels cool, but resilient underneath at
first. This is followed by white skin
that is cold and hard. Finally, the
skin will become red and swollen. Skin
that has frozen will form blisters upon thawing and some areas of skin may
appear black, indicating that the tissue has died.
Frostbite Treatment
Important Note: when
frostbite is accompanied by hypothermia, the hypothermic condition must be
treated first and medical attention must be promptly sought. Conditions requiring first aid should be
attended to immediately.
FROSTBITE
DOs
DO
shelter the victim from the cold
DO
remove clothing from the affected region
DO
remove articles such as watches and rings that can restrict blood flow
DO
rewarm the affected area by covering with warm hands or clothing
DO
immerse affected parts in warm (less than 110 degrees Fahrenheit) water, if
available
DO
cover treated areas with sterile dressings
The
armpits are a good source of warmth for warming frostbitten extremities. The victims hands can be placed under the armpits
to warm. The person providing on site
treatment can use his or her armpits to warm a victim’s feet.
FROSTBITE
DO NOTs
DO
NOT rub or message the affected body parts
DO
NOT use direct heat to warm affected body parts
DO
NOT promote movement of the affected body parts
DO
NOT allow frostbite victims to walk on frostbitten feet
DO
NOT attempt to burst blisters that form during thawing
Hypothermia
Prolonged
exposure to extremely low weather conditions, immersion in cold water (rivers,
lakes, oceans), and wearing wet or damp clothing in cold conditions can lead to
hypothermia (also referred to as systemic hypothermia). The very young and the very old are the most
susceptible to the development of hypothermia due to a decreased (or
incompletely developed) ability to compensate for body temperature loss. When exposures cause the body’s temperature
to fall below 95 degrees Fahrenheit, the person is considered to be suffering
from hypothermia. Hypothermia is most accurately
diagnosed by measurement of the body temperature rectally.
Symptoms
A
person suffering from even mild hypothermia will have a slowed heart rate and
usually will exhibit drowsiness and confusion.
Characteristically, the skin will be pale and the face will appear
puffy. Areas of the skin that are
normally warm to the touch, such as the armpits, will be cold. In the case of severe hypothermia, the depth
and rate of breathing will change. The
victim will breathe more slowly and take more shallow breaths. The victim’s muscles may become stiff and
loss of consciousness is possible. In
the most severe cases (where the core body temperature falls below 90 degrees Fahrenheit),
the heart may beat only faintly, the heartbeat may become irregular, or the
heart may stop altogether.
Treatment
In
the most mild cases of hypothermia, removing the victim from the cold, removing
any wet or damp clothing, covering the head and shoulders and providing the
conscious victim warm (not hot) liquids may be sufficient to induce recovery. Even in these types of cases, the victim
should receive medical attention. In
more severe cases, a young and otherwise healthy individual can be warmed in a
warm bath (not too hot though). Infants
and the elderly can suffer adverse health effects from immersion in warm
water. This is especially true in the
elderly where such treatment could result in a lowered flow of blood to the
heart and brain by increasing the blood flow to the surface of the body.
Hypothermia
DOs
DO
seek medical help for those suspected or known to be hypothermic
DO
begin CPR if the victim is not breathing
DO
move the victim to a warm place
DO
take off wet clothing, re covering the victim with dry covers (water-proof
where necessary)
DO
provide warm beverages (not hot) to conscious victims (you may need to help
steady the cup)
DO
allow younger and otherwise healthy individuals to warm in a tub with warm (not
hot) water.
Hypothermia
DO NOTs
DO
NOT message or rub the victims skin
DO
NOT provide beverages to unconscious victims
DO
NOT give alcohol to victims
DO
NOT warm the victim using direct heat sources
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Consulting, Inc. provides the safety articles contained on our website as a
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