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Cold-Related Emergencies. When surrounded by air or water cooler than body temperature, body loses heat.Normal body temperature is 98.6?F.If heat escapes faster than the body produces it, the body temperature falls, and cold injuries result. . How Cold Affects the Body (1 of 2). The body has two i
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1. Chapter 20 Cold-Related Emergencies
2. Cold-Related Emergencies When surrounded by air or water cooler than body temperature, body loses heat.
Normal body temperature is 98.6?F.
If heat escapes faster than the body produces it, the body temperature falls, and cold injuries result.
3. How Cold Affects the Body (1 of 2) The body has two internal mechanisms to maintain body temperature.
Vasoconstriction
Tightening of blood vessels
Can cause discomfort, numbness, loss of dexterity, cold injuries
Shivering
Stops when core temperature falls between 86?F and 90?F
4. How Cold Affects the Body (2 of 2) Physical activity produces heat.
Heat loss increases if clothes become wet with perspiration.
Susceptibility can be minimized by:
Proper hydration and nutrition
Avoiding alcohol, caffeine, and nicotine
Limiting periods of inactivity
5. Heat Loss from the Body (1 of 2) Four mechanisms of heat loss:
Conduction
Direct contact with colder object
Convection
Loss of heat by air blowing over skin
Evaporation
Conversion of liquid on skin to vapor
6. Heat Loss from the Body (2 of 2) Four mechanisms of heat loss (cont’d):
Radiation
Heat given off to cooler air
Accounts for the greatest heat loss
7. Susceptibility to Cold Injury Physically unfit
Dehydration
Very lean people
Elderly people
Alcohol, caffeine
Nicotine
Inadequate nutrition, illness, injury
Experienced a previous cold injury
8. Effects of Altitude Air temperature drops 3.6?F every 1000 feet.
Winds are more severe.
More susceptible to frostbite above 8000 feet
9. Effects of Water Water can conduct heat away from the body much faster than air of the same temperature.
Wet clothing accelerates heat loss.
10. Effects of Wind Wind increases heat loss from skin exposed to cold air.
Windchill is the combined effect of the ambient temperature and wind speed.
11. Effects of Metal and Liquid Fuels Can conduct heat away from skin rapidly
Contact can cause almost instantaneous freezing.
12. Minimizing Effects of Cold on the Body (1 of 2) Layering
Undergarment removes perspiration.
Wicking properties
13. Minimizing Effects of Cold on the Body (2 of 2) Middle layer insulates.
Should be effective when wet
Synthetics are better than natural fibers.
Wool
Outer layer protects against wind.
Waterproof
Wind resistant
“Breathable”
Hat
14. Nonfreezing Cold Injuries Can occur when conditions are cold and wet and hands and feet cannot be kept warm and dry
15. Chilblain Is painful
Causes little or no permanent damage
Can develop in 3 to 6 hours
16. Recognizing Chilblain Swollen skin
Skin is tender, hot to the touch, and possibly itchy.
Blisters
Aching, prickly sensation, numbness
17. Care for Chilblain Get victim out of cold.
18. Trench Foot Develops when skin on the feet is exposed to moisture and cold for 12 hours or longer
Caused by:
Wearing wet boots and shoes
Prolonged immersion of the feet in cold water
Rubberized or tight-fitting boots increase risk.
19. Recognizing Trench Foot and Immersion Foot Itching, numbness, tingling pain
Swollen feet and pale skin cold to touch
Red or bluish blotches on the skin
Sometimes open weeping or bleeding
20. Care for Trench Foot Dry the skin.
Rewarm foot gradually.
Care for open weeping areas.
Use mild soap and water.
Apply a breathable dressing.
21. Freezing Cold Injuries Occur when air temperature is below freezing
Frostnip
Freezing is limited to skin surface.
Frostbite
Freezing extends into the flesh.
22. Frostnip Frostnip is caused when water on the skin surface freezes.
23. Recognizing Frostnip Red and sometimes swollen skin
Painful
Repeated frostnip can dry the skin.
24. Care for Frostnip Gently warm affected area.
Do not rub the affected area.
25. Frostbite Two ways of damage:
Tissue freezing
Obstruction of blood supply to the tissue
Affects feet, hands, ears, and nose
26. Recognizing Frostbite (1 of 2) White, waxy, or grayish yellow skin
Part feels cold and numb.
Tingling, stinging, aching
Stiff or crusty skin
Underlying tissue is soft.
27. Recognizing Frostbite (2 of 2) Indications of deep frostbite:
Part feels cold, hard, and solid and cannot be depressed.
Blisters
Pale, waxy skin
Painfully cold part suddenly stops hurting.
28. Classifications of Frostbite First-degree
Warm, swollen, and tender
Second-degree
Blisters form.
Enlarges over several days
29. Care for Frostbite (1 of 2) Get victim to warm area.
Remove wet clothing and constricting items.
Seek medical care.
If affected part is partially thawed:
Place part in warm water.
Maintain water temperature.
20 to 40 minutes
Give pain medication.
Apply warm cloths to ear or facial injuries.
30. Care for Frostbite (2 of 2) After thawing:
Treat the victim as a stretcher case.
Protect area from contact with clothing and bedding.
Place dry gauze between toes and fingers.
Slightly elevate the affected part.
Apply aloe vera gel.
Provide pain medication.
31. Hypothermia A life-threatening condition in which the body’s core temperature falls below 95?F
Body loses more heat than it produces.
Heartbeat/breathing may be undetected.
Begin cardiopulmonary resuscitation (CPR) immediately.
Consider whenever victim’s behavior and history and the weather conditions indicate abnormal heat loss
32. Types of Exposure Acute
Usually in water
6 hours or less
Subacute
6 to 24 hours
Land or water
33. Hypothermia Symptoms Change in mental status
Disorientation
Apathy
Changes in personality
Shivering
Cool abdomen
Low core body temperature
34. Types of Hypothermia Mild to severe based on core body temperature
In severe cases, shivering stops.
Do not start CPR if:
Core body temperature is below 60?F.
Chest is frozen.
Submerged in water for more than 60 minutes.
A lethal injury exists.
Transport will be delayed.
Rescuers are endangered.
35. Recognizing Mild Hypothermia Vigorous, uncontrolled shivering
Decreased mental skills
Slurred speech
Difficulty using fingers or hands
Staggers while walking
Cool or cold skin on abdomen, chest, or back
Core body temperature above 90?F
36. Care for Mild Hypothermia Get victim out of cold.
Handle gently.
Prevent heat loss.
Cover the victim with a vapor barrier.
Keep the victim horizontal.
Call 9-1-1.
Allow the victim to shiver.
Give warm, sugary drinks.
37. Recognizing Severe Hypothermia No shivering
Ice cold and blue skin
Stiff and rigid muscles
Altered mental status
Slow breathing and pulse
Might appear dead.
Core body temperature is below 90?F.
38. Care for Severe Hypothermia Get victim out of the cold.
Handle gently.
Prevent heat loss.
Cover with vapor barrier.
Keep victim horizontal.
Call 9-1-1.
When remote, warm by available heat.
39. Adding Heat Problems with rewarming:
Warm water immersion requires a lot of warm water and a bathtub.
Body-to-body contact in insulated sleeping bag is not better than shivering.
No evidence that chemical heating pads are capable of rewarming a hypothermic victim.
40. Dehydration (1 of 2) Occurs because of unperceived fluid loss combined with inadequate fluid intake
Cold weather: fluid lost through breath
Drink even if not thirsty.
Inactive: drink 2 quarts of water daily
Color and volume of urine indicate hydration.
41. Dehydration (2 of 2) Unmelted snow and ice should not be consumed for water.
Irritates the mouth
Wastes body heat
Lowers body temperature
Be sure snow and ice are disinfected before consumption.