                          Out In The Cold
                       by Brita M. O'Carroll

   Ŀ
    Objectives                                                
    After reading this article, the reader should be able to: 
                                                              
    1.  Describe five ways by which the body loses heat.      
    2.  Define three factors that determine the severity of    
        local cold injury.                                    
    3.  Describe the signs and symptoms of frostbite.         
    4.  Describe the proper steps for the five stages of       
        hypothermia.                                          
    5.  List the signs and symptoms for the five stages of     
        hypothermia.                                          
    6.  Describe the proper field treatment for a person       
        suffering from hypothermia.                           
   

You are in a northern metropolitan area.  A heavy snowstorm is in
progress, and traffic is jammed on major roads.  A call comes in
reporting a stalled car with a person slumped over the steering
wheel.  It is 9 p.m.

At the scene, a man in his mid-30's is unconscious.  His skin is
cold, radial pulses cannot be felt, respirations are eight per
minute, and there seems to be an odor or alcohol on his breath. 
What do you do?

Physiology of Cold
The body works to maintain a temperature of 98.6 degrees F and
has only a narrow temperature range in which systems and chemical
reactions can operate efficiently.  There must be a balance
between heat generated, heat absorbed from the environment and
heat loss, or problems will arise.

Just as the body has a mechanism to protect itself when exposed
to heat, it also has defense mechanism for reacting to exposure
to cold.  Response to both heat and cold originates in the
hypothalamus, the thermoregulatory center of the brain.  In the
case of cold exposure, the primary function of the hypothalamus
is to prevent the core temperature from cooling too much.

When the body's temperature is greater than that of the
environment, it will lose heat, since heat always travels from
areas of higher temperature to areas of lower temperature.  Loss
of body heat can occur in the following ways:

*    Conduction occurs as heat passes directly from the body or a
     part of the body to a colder object, such as when a hand
     touches a frozen ice cube tray, or when the body is immersed
     in water that has a temperature of less than 98 degrees F.

*   Convection occurs when heat moves through the air to a
     cooler area by passing across the body's surface.

*    Evaporation requires body heat and is the conversion of a
     liquid into a gas, as seen with perspiration or water
     evaporating  from the skin's surface.

*    Respiration causes a loss of body heat when warm air in the
     lungs is exhaled into the atmosphere.

*    Radiation occurs when warmer objects, such as the body, give
     off heat to a cooler environment, as when sitting in a cold
     automobile.

The rate and amount of heat lost by the body can be changed by
modifying the way any or all of these mechanisms function.

Cold-related Emergencies
Cold-related emergencies include local and/or systemic cooling. 
Local cooling targets specific areas, while systemic cooling
generally affects the entire body.  It is important to remember
that both localized and systemic problems can occur
simultaneously.

Local cooling - Many cold-related injuries are localized to
exposed parts of the body, especially the ears, nose, hands and
feet.  Cold air or liquid causes the superficial vessels of the
skin to constrict, which decreases blood flow to the affected
area.  The tissues may not receive enough warmth to prevent them
from freezing, and ice crystals may form on the skin.  The injury
can progress to tissue death (gangrene) and possible loss of the
affected body part.

Specific factors that make a person more susceptible to local
cold injury include:  inadequate insulation from cold weather,
wind or liquids; restricted circulation from tight clothing and
shoes or circulatory disorders; fatigue; poor nutrition; alcohol
or drug abuse and smoking; and hypothermia.

The three most important circumstances determining the severity
of local cold injury are duration of exposure, the temperature in
which the exposure occurred and wind velocity during exposure.

Chilblains
Seen in cold, damp climates, chilblains are lesions that occur
from repeated, prolonged exposure to temperatures below 60
degrees F.  Small, red, swollen areas under the surface of the
skin are painful, hot and itchy.  The condition is chronic and
without serious consequences.  There is no "emergency" care
required, other than protecting the area and trying to prevent
recurrence.  Since you are not in the business of providing
diagnosis, recommend that the patient be seen by a physician for
follow-up and confirmation of the problem.

Trenchfoot
Although the physiology is similar to frostbite, this injury can
occur in warm climates.  Also called "immersion foot," from being
in water of lower temperatures than that of the body, the tissues
become edematous and soft and have local vasculitis.  The
affected area will often appear pale, mottled and pulseless.  It
feels cold to the touch and to the patient, who may also complain
of numbness.

Management - Remove shoes, socks and any other wet clothing.  If
blisters have developed, do not open them.  Gently rewarm the
affected limb, pad between the toes, and warp lightly with a
sterile dressing.  Keep the limb slightly elevated.  After
rewarming, drying and elevating the limb, it may develop red
areas from increased circulation (hyperemia) and become very
painful.

Severe disability can occur with trenchfoot, and the risk of
infection is high.  Careful tissue protection and transportation
to a medical facility should follow initial patient management.

Frostnip
The first stage of frostbite, frostnip is caused by prolonged
exposure to cold air, wind or water.  This condition typically
takes some time to develop, with victim often unaware of the
problem until someone else calls attention to a change in skin
color.

Most often, the peripheral extremities or surfaces of exposed
skin, such as the face, are affected.  Although extremely cold,
the tissues of the outer surface of the body will not be frozen. 
The skin first reddens, then blanches and has a frosty sheen. 
There is a feeling of tingling followed by burning skin
sensations and numbness.

Management - When the patient is removed from the source of cold
and gently warmed, frostnip resolves rapidly.  If response is not
fast, treat for frostbite.  There should not be any serious
consequences.

Frostbite
Frostbite is the most serious of the localized cold injuries, in
which tissue cells are actually frozen.  Most often, isolated
parts, such as the ears, nose, hands and feet, are affected. 
Damage occurs from prolonged or intense contact with cold, as
with sudden and extreme temperature drop, exposure to cold metal
and becoming wet in wind chill or at high altitudes.  However,
frostbite can even occur in warmer weather.

With the body's attempt to maintain its core temperature, the
peripheral vasoconstriction causes more blood to flow to the
vital organs, which sacrifices circulation to the extremities. 
Fast cooling of the affected area allows ice crystals to form,
causing cellular damage and tissue edema.  Frostbite can vary in
severity and extent.

In the case of superficial frostbite, the skin is frozen, but the
deeper tissues are not.  The area looks white and waxy, feeling
frozen on the surface, though the underlying tissue is soft and
has good resilience.  The patient will relate a history of
progressive coldness leading to tingling and numbness ("wooden
stump" sensation).

Deep frostbite has signs and symptoms of freezing.  The skin
turns mottled or blotchy, with the color changing from white to
grayish-yellow and eventually to grayish-blue.  The surface feels
frozen to the touch, and deeper tissues lose their rebound
elasticity.

Management - Note:  Do not poke or squeeze the affected area, as
the tissue is extremely fragile.  Touching the injured area very
gently is enough to determine the condition of the deeper
tissues.  Never rub the area briskly or put frozen snow on the
site, as by-standers might suggest.

If the patient can be transported to a hospital, do so
immediately.  Protect the affected by covering it carefully and
handling it as little as possible.

If transport must be delayed, move the patient indoors and keep
him warm.  Do not allow him to smoke, as smoking further
constricts  vessels that are already suffering from decreased
circulation.  Discourage the consumption of alcohol.

Rewarming should follow local protocol or orders from medical
control.  In the absence of protocols or specific orders,
management of frostbite should include the following:

If a limb is involved, keep warm water available or a container
for heating water.  Another container should be available in
which to submerge the injured area without touching the sides or
bottom (a plastic bag supported by a box or garbage can will also
work).

Warm the water to the point that you can put your finger into it
without discomfort.  Most resources recommend that the water be
104 degrees F to 109 degrees F for immersion warming.  Remove any
covering, jewelry, bands or straps from the limb.  Fully immerse
the injured part, without touching the sides or bottom, ensuring
that no pressure is placed on the limb.  Maintain the water
temperature at 104 degrees F to 109 degrees F, replenishing when
necessary.

There may be intense pain as the area warms, which is a sign of
improving circulation.

If the limb rewarms to the point of being either red or blue and
not feeling frozen, dry gently and apply a sterile dressing,
placing padding between fingers or toes.
Cover the site with light blankets, ensuring that they do not
come into direct contact with, or put pressure on, the injury.  
Keep the patient at rest, and do not allow him to walk if a lower
extremity is involved.  Check for general hypothermia, continue
to monitor the patient, assist circulation by raising and
lowering the limb, and transport as soon as possible, keeping the
limb slightly elevated and the patient warm.

General/Systemic Cooling
Hypothermia is a relative state.  Humans have a tropical internal
environment, with a core temperature of 101 degrees F.  General
cooling of the body, resulting in a series of symptoms of
progressive severity as the core temperature drops, is known as
systemic hypothermia.

Exposure to cold pulls heat from the body.  A slight drop in body
temperature triggers the regulatory mechanisms to increase heat
by shivering, which generates heat through muscle activity, and
cutaneous vasoconstriction (in which vessels in the skin become
smaller), which shunts blood away from the skin and cold.

As the body gets colder, maintaining the core temperature becomes
increasingly difficult.  Basal metabolism (the amount of energy
needed at rest to maintain life) cranks up in an attempt to
increase heat production.  Yet the more the environmental cold
causes the body temperature to drop, the more the regulatory
system flounders, with metabolism producing less heat and the
body temperature continuing to fall.
When the temperature regulator becomes overwhelmed, failure
continues, and all body systems are affected.  Ventilation
weakness because the respiratory control center is depressed. 
Oxygen consumption and carbon dioxide production diminish.  A
cycle begins of decreasing metabolic heat production, falling
core temperature, failure of organ systems, depressed
respirations and increasing anoxia.  The cardiac muscle
(myocardium) is at risk and can begin to fibrillate.  Without
intervention, anoxic death will follow.  

During this process, when central and peripheral signs of cold
stress appear, the resulting physical problems can seem
conflicting and may adversely affect each other.  Therefore, it
is important to take into account all symptoms for proper
management.

It is essential not to assume too soon that death has occurred: 
the hypothermia victim is not dead until he is warm and dead.

Patient Assessment
As with every patient, first check the ABCs of airway, breathing
and circulation.  Not the level of consciousness.  Is the patient
drowsy, unwilling to follow even the simplest of commands, or
unconscious? 

Is the patient shivering?  Shivering occurs in the first stage of
hypothermia.  With a body temperature of 99 degrees F to 96
degrees F, the patient experiences intense, often uncontrollable
shivering.  From 95 degrees F to 91 degrees F, shivering is
violent.  If the victim is conscious, speech is difficult.  Below
90 degrees F, shivering stops.

Is there localized cold injury?  Is there an odor of acetone on
the breath?  Do not confuse acetone with the odor of alcohol. 
What is the level of muscular function?  Second stage occurs when
the core temperature is 90 F to 86 degrees F, and muscle
coordination is affected.  Erratic, jerky movements occur. 
Small, fine muscle activity, such as coordinated finger motion,
ceases.  Thinking is impaired, and general comprehension is
dulled even to the point of amnesia.  Is vision diminished? 
Eyesight fails in cases of prolonged hypothermia.

Third-stage temperature is 85 degrees F to 81 degrees F.  The
patient may be irrational and lose contact with his environment
or lethargic and lose interest in fighting the cold.  Muscular
rigidity occurs.  Pulse and respirations become very slow, and
cardiac arrhythmias can develop.

At 80 degrees F to 78 degrees F, (the fourth stage), vital signs
significantly decrease, and the patient loses consciousness.  
Most reflexes cease to function, and the heartbeat is erratic.

Below 78 degrees F, the cardiac and respiratory centers of the
brain fail, ventricular fibrillation occurs, pulmonary edema and
hemorrhage are possible, and death is imminent.

The fifth stage occurs when all cardiorespiratory activity is
completely absent.  Death may be apparent, but even these
patients have been revived, especially in cold-water, near
drowning victims.  The patient may be in a "metabolic ice-box,"
and if further heat loss can be prevented, successful
resuscitation is possible.

Management - Note:  Rewarming a patient with mild hypothermia in
the field is allowed by some EMS systems; it is dangerous, and
the patient's condition may be more serious than it had initially
appeared to be.  If your protocol permits rewarming, do not delay
transport, rewarm in transit, and stay in contact with medical
control.

Mild hypothermia management - Handle the patient with as much
care as you would an unstabilized spinal-cord-injury patient, as
his system is very fragile.  Transport should be immediate, with
procedures administered on the way to the medical facility; the
patient should be treated at the location only if immediate
transport is not possible.  Conduct patient surveys and
interviews to determine the extent of the problem.  Remove all
wet clothing, replacing with dry items or blankets.

Initial rewarming should be limited to the core, meaning that 
heat should be applied to the trunk, armpits and groin, but not
to the limbs.  If the limbs are warmed first, vasodilation will
cause blood to collect in the extremities, possibly leading to
fatal hypovolemic shock.  Rewarming the trunk and leaving the
lower extremities exposed allows for better control of the
heating process.

Use heat in the form of warm packs, hot water bottles, electric
pads, hot air, radiated heat or your own body to raise the core
temperature.  Do not warm the patient too quickly.  Rapid warming
will circulate the stagnated, cold peripheral blood, which will
cool the vital central areas of the body, possibly causing
ventricular fibrillation.  Rewarming only with blankets does not
help much, as the patient can no longer generate enough internal
heat to make surface covering useful.  External heat is
necessary.  Monitor the patient constantly, especially if loss of
consciousness has occurred.

Keep the patient at rest.  Do not allow walking, which will
circulate cold peripheral blood to the core areas, and may set
off severe problems such as cardiac arrhythmias.  If the patient
is alert, give warm liquids slowly.

Provide care for shock, and administer oxygen.  Do not use oxygen
from a cold cylinder unless no other option is available.  Never
allow a patient to remain in, or return to, a cold environment,
as hypothermia will probably recur.

Severe hypothermia management:  Do not try to rewarm the patient
with severe hypothermia.  Even if rewarmed slowly, the patient
may develop lethal ventricular fibrillation.  Handle the patient
as gently as possible; rough movement may cause ventricular
fibrillation.  Place the patient in a head-down position. 
Administer a high concentration of oxygen that has been passed
through a warm water humidifier.  If this method is unavailable,
any high concentration of oxygen is acceptable.  Wrap the patient
in blankets, using an insulating blanket if available.  Transport
immediately.

In extreme cases, the victim is unconscious, with no apparent
vital signs, and very cold to touch.  Core temperatures may be
below 80 degrees F, but it is possible to resuscitate some of
these patients.  Therefore, assess the carotid pulse for one full
minute.  Begin CPR right away, as biological death may be
considerably delayed due to the hypothermia.  The ED staff will
not declare the patient biologically dead until he has been
rewarmed as resuscitative measures are conducted.

Hypothermia patients cannot be assumed dead only on the basis of
body temperature and lack of vital signs.  Usually the lowest
temperature for survival is about 23 degrees F, but most
hypothermia patients with accidental hypothermia die sooner.  One
of the lowest temperatures recorded for an accidental hypothermia
survivor is 64.4 degrees F.  Another known situation is that of a
patient whose core temperature plummeted to 10 degrees F and who,
when found, had been in cardiac arrest for an hour.

Management of cold exposure in sick or injured person - You may
come across a sick or injured person who has been trapped in a
cold environment and has developed hypothermia or problems
related to localized cold exposure.  Prompt action will prevent
further injury.  Protect the accident victim before extrication
and throughout care and transport by preventing body-heat loss as
much as possible.  If the victim must remain trapped for some
time, plug holes and provide any other protection from the
elements.  Remove wet clothing and keep the patient dry.  Prevent
conduction heat loss:  Do not allow the patient to lie against
any wet or cold surfaces.  Insulate all exposed parts of the
body, especially the head, through which a great deal of heat may
be lost, by wrapping with  a blanket, salvage cover, aluminized
blanket, survival blanket or any other dry material, even plastic
bags.  Prevent convection heat loss by putting a barrier around
the patient to protect him from the wind.  Remove the patient
from the cold and/or environmental elements as soon as possible.

Conclusion
Cold-related injuries can be localized or systemic.  Localized
injuries usually affect the extremities after exposure to cold
objects or conditions.  Unless severe damage has been sustained,
medical management should be basic, with relatively few
complications.

Hypothermia is a condition in which body temperature is
decreased.  As the core temperature falls, the thermoregulatory
mechanism experiences increasing difficulty in functioning
properly.  Metabolism initially increases in an attempt to
produce heat but then slows, becoming significantly disrupted. 
The respiratory system becomes depressed.  As each system
malfunctions, the prognosis worsens.  Ultimately, the hypothermic
patient may appear to be dead:  pulseless, apneic and with fixed
and dilated pupils.  However, slowing or internal chemical
processes reduces metabolic demands, which increases the
potential for survival. 

Glossary
Anoxia - An abnormal condition characterized by a lack of oxygen. 
It may be local or systemic.  It may be the result of an
inadequate supply of oxygen to the respiratory system, an
inability of the blood to carry oxygen to the tissues, or an
inability of the tissues to absorb oxygen from the circulation.

Edematous - Pertaining to or affected by edema, which is the
abnormal accumulation of fluid in spaces of tissues.

Vasculitis - An inflammatory condition of the blood vessels.

Vasoconstriction - A narrowing of the opening in a blood vessel,
especially the arterioles and the veins in the blood reservoirs 
of the skin and abdominal organs.

References
1.   American Academy of Orthopedic Surgeons:  Emergency Care and
     Transportation of the Sick and Injured.  Fourth Ed. Park
     Ridge, Ill.:  American Academy of Orthopedic Surgeons, 1987.
2.   Caroline NL:  Emergency Care in the Streets.  Third Ed.
     Boston:  Little, Brown and Co., 1987.
3.   Grant H, et al:  Emergency Care. Fifth Ed., Englewood
     Cliffs, N.J.:  Brady Publishing, 1990.
4.   Judd RL, Ponsell DD:  Mosby's First Responder.  Second Ed.
     St. Louis:  C.V. Mosby Co., 1988.
5.   Kitt, Kaiser:  Emergency Nursing, A Physiologic and Clinical
     Perspective.  First Ed. Philadelphia:  H.B.
     Saunders/Harcourt Brace Jovanovich Inc., 1990.
6.   U.S. Department of Transportation:  Emergency Medical Care. 
     Washington, D.C.:  U.S. Government Printing Office, 1987.

Brita M. O'Carroll has been working in EMS for 20 years in local,
state, regional, national and international arenas.  She is a
Florida board member of the American Medical Writers Association.






                              TEST
                         Cold Emergencies

1.   The center in the brain that regulates responses to both
     heat and cold is the:

     a.   thalamus
     b.   cortex
     c.   hypothalamus
     d.   medulla

2.   Conduction is the means by which the body loses heat
     primarily through:

     a.   air as it passes across the body's surface
     b.   direct bodily contact with a colder object
     c.   conversion of a liquid into a gas
     d.   liquid droplets

3.   Specific factors that make a person more susceptible to
     local cold injuries include all of the following except:

     a.   restricted circulation from tight clothing
     b.   fatigue, drug abuse and smoking
     c.   inadequate insulation from cold weather and alcohol
          consumption
     d.   coffee consumption

4.   Signs of trenchfoot include:

     I.   edema
     II.  pale color
     III. deformity
     IV.  mottled appearance
     V.   pulselessness

     a.   I, III, V
     b.   I, II, IV, V
     c.   II, III, IV
     d.   all of the above

5.   Management of trenchfoot includes the following:

     I.   elevation of the affected limbs
     II.  removal of wet clothing
     III. gentle rewarming
     IV.  application of sterile dressings

     a.   I, IV
     b.   I, III
     c.   II, IV
     d.   II, III, IV
     e.   all of the above
6.  The areas of the body most commonly affected by frostbite
     include all of the following, except:

     a.   hands
     b.   feet
     c.   ears
     d.   knees
     e.   nose

7.   The most serious localized cold injury is:

     a.   trenchfoot
     b.   frostnip
     c.   chilblain
     d.   frostbite

8.   Deep frostbite presents with the following signs and
     symptoms:

     I.   the skin feels frozen on the surface and hard
          underneath
     II.  the skin appears white and waxy 
     III. skin color is white, grayish-yellow or grayish-blue
     IV.  the skin feels frozen on the surface and soft
          underneath

     a.   I, II
     b.   I, III
     c.   II, IV
     d.   none of the above

9.   The following should be avoided in a person suffering from
     frostbite:

     I.   rubbing with snow
     II.  touching the skin's surface
     III. smoking
     IV.  consuming alcohol

     a.   I, IV
     b.   I, III
     c.   II, IV
     d.   II, III, IV
     e.   all of the above

10.  When rewarming a frostbite limb in water, the water
     temperature should be:

     a.   105 to 112 degrees F
     b.   104 to 109 degrees F
     c.   98.6 to 105 degrees F
     d.   110 to 115 degrees F
11. Any time a patient has suffered frostbite, you should also
     check for:

     a.   general hypothermia
     b.   trenchfoot
     c.   a cardiac pacemaker
     d.   deep tendon reflexes

12.  When the thermoregulatory mechanism becomes overwhelmed,
     which of the following changes occur?

     I.   ventilation weakness
     II.  carbon dioxide production diminishes
     III. core temperature falls
     IV.  risk of fibrillation increases
          
     a.   I, II, III
     b.   II, III, IV
     c.   I, III, IV
     d.   all of the above

13.  The cardiac and respiratory centers of the brain fail at
     what temperature?

     a.   below 98 degrees F
     b.   below 85 degrees F
     c.   below 78 degrees F
     d.   below 74 degrees F

14.  Which of the following is not an effective means of
     rewarming the core temperature of a patient with mild
     hypothermia?

     a.   warm packs
     b.   hot water bottles
     c.   electric pads
     d.   radiated body heat
     e.   blankets

15.  In extreme cases of hypothermia, you should assess the
     carotid pulse for;

     a.   15 seconds
     b.   30 seconds
     c.   60 seconds
     d.   45 seconds
     e.   5 seconds

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