Chapter 15 Physical and Environmental Hazards

Lesson Objectives (1 of 3) List the body’s physiological changes during acclimatization. Predict and prevent acute mountain sickness (AMS).

Lesson Objectives (2 of 3) Assess and manage AMS, including high altitude pulmonary edema and high altitude cerebral edema. Assess and manage cold weather injuries, including hypothermia, frostbite, immersion (trench) foot, and chilblains.

Lesson Objectives (3 of 3) Assess and manage heat illnesses, including heat exhaustion, heatstroke, and heat cramps. List lightning safety guidelines and know how to assess and manage injuries caused by lightning.

Overview Altitude, extreme temperatures, wind, rain, and lightning cause injuries and illnesses that do not commonly occur in urban areas. © Simon Krzic/ShutterStock, Inc.

Acclimatization (1 of 2) The physiological changes in the body that compensate for hypoxia at altitudes above 8,000 feet. Best achieved through slow, progressive ascent. Rate and depth of breathing increase to improve oxygen delivery to the blood.

Acclimatization (2 of 2) Heart beats more quickly and strongly. Bone marrow produces more red cells. Number of capillaries increase.

Acute Mountain Sickness (1 of 10) Travel above 8,000 feet results in lower levels of oxygen in the blood. AMS strikes those who ascend too high too fast and those who have not acclimatized to high altitudes.

Acute Mountain Sickness (2 of 10) Predicting AMS –Cannot predict who will suffer. –Those who have suffered AMS before are more likely to experience it. –Fitness and training offer no guaranteed protection.

Acute Mountain Sickness (3 of 10) Prevention of AMS –Allow ample time to acclimatize at various levels of ascent. High altitude climbing –Mild AMS can develop at 6,000 feet. –Above 13,000 feet, climbers should reach sleeping altitude about 1,000 feet higher than the previous day.

Acute Mountain Sickness (4 of 10) High altitude climbing (continued) –Climbers who become sick and do not improve must descend 1,000 to 3,000 feet. –Drink 4 to 5 quarts of fluid daily. –Avoid alcohol, sedatives, and sleeping pills.

Acute Mountain Sickness (5 of 10) Mild AMS –What to look for: Headache that often develops at night Unusual fatigue Appetite loss and nausea Restless sleep with irregular breathing Shortness of breath with exertion Swollen face with bags under the eyes

Acute Mountain Sickness (6 of 10) Mild AMS –What to do: Rest and do not go any higher. Administer aspirin or acetaminophen. If symptoms increase, descend. Administer acetazolamide. Give dexamethasone for severe headache. Be alert for progression to severe altitude sickness.

Acute Mountain Sickness (7 of 10) High altitude pulmonary edema (HAPE) –What to look for: Shortness of breath Cough producing frothy, blood-stained sputum Rattling or crackling and moist breathing Cyanosis Rapid pulse

Acute Mountain Sickness (8 of 10) High altitude pulmonary edema (HAPE) –What to do: Descend. Give oxygen. Commence treatment in portable compression chamber. Administer acetazolamide and/or nifedipine.

Acute Mountain Sickness (9 of 10) High altitude cerebral edema (HACE) –What to look for: Severe, constant throbbing headache Incoordination Extreme fatigue not relieved by rest Hallucinations Vomiting Coma

Acute Mountain Sickness (10 of 10) High altitude cerebral edema (HACE) –What to do: Descend. Treat for several hours in a portable hyperbaric bag. Prop victim up to improve breathing. Give 4 to 5 liters of fluid daily. Administer acetazolamide and dexamethasone.

Cold Injury (1 of 20) Cold injuries include hypothermia, frostbite, cold immersion injury, and chilblains. Hypothermia is a general cooling of the body core that develops when the body’s temperature drops more than 2 º F. Frostbite is freezing of skin and flesh.

Cold Injury (2 of 20) Hypothermia –Exacerbated by inadequate clothing and exhaustion –Anxiety, injury, drugs, alcohol, and poor nutrition predispose people to hypothermia. –Wetness and wind chill can cause hypothermia in all seasons.

Cold Injury (3 of 20) Hypothermia –Means of heat loss Convection Conduction Evaporation Radiation

Cold Injury (4 of 20) Hypothermia –Sources of heat gain Radiation Exercise Shivering Food Blood vessel constriction Insulation

Cold Injury (5 of 20) Mild hypothermia –What to look for: Shivering Uncharacteristic behavior Stiff muscles and cramps Cold, pale, and blue-gray skin

Cold Injury (6 of 20) Mild hypothermia –What to do: Find shelter. Light a fire or stove. Change or remove wet clothes and add dry layers. Give food and hot drinks. Allow shivering to continue inside a sleeping bag.

Cold Injury (7 of 20) Mild hypothermia –What to do: Give warm, sweet liquids. Provide rest and warmth. Never leave a hypothermic victim alone!

Cold Injury (8 of 20) Severe hypothermia –What to look for: No shivering Behavior changing from erratic to apathetic to unresponsive Stiff muscles and uncoordinated movement Weak, slow, irregular pulse Slow breathing Coma, with dilated pupils

Cold Injury (9 of 20) Severe hypothermia –What to do in the field: Concentrate effort on reducing further heat loss. Do not endanger other members of the party. Shelter the victim. Stop further heat loss. Provide heat to the victim’s trunk. Cover the victim’s head.

Cold Injury (10 of 20) Severe hypothermia –What to do (rescue): Leave at least one person with the victim. Send for help. Do not change your plan, even if victim improves. If you must carry the victim out, insulate him or her well. Choose the safest route.

Cold Injury (11 of 20) Severe hypothermia –What to do (base camp): If rescue is impossible or days away, use all available means to rewarm the victim slowly. Do not try rapid rewarming. Give plenty of warm, sweet liquids. Do not place warm objects directly on the victim’s skin.

Cold Injury (12 of 20) Deep hypothermia –Body core temperature falls below 82 º F. –Pupils can be dilated and fixed, the limbs stiff, and the skin icy. –Should attempt resuscitation if there is even a remote chance at recovery. –Only sure sign of death is failure to revive with rewarming.

Cold Injury (13 of 20) Immersion hypothermia –Has rapid onset and a faster rate of cooling –Heat loss is 25 times faster in water than in air. –Can develop in less than an hour in water colder than 45 º F. –Begin CPR as soon as possible.

Cold Injury (14 of 20) Frostbite –Localized freezing of tissues. –Contributing factors include: wetness, contact with metal, prolonged exposure, dehydration, poor nutrition, extremely cold temperatures, and immobilization.

Cold Injury (15 of 20) Frostbite –Types of frostbite Frostnip: Superficial injury involving the surface of the skin Superficial frostbite: Involves all layers of skin but not underlying fat, muscles, or other tissue Deep frostbite: Involves the skin and underlying tissues

Cold Injury (16 of 20) Frostbite –What to look for: White, waxy skin that has no feeling and is wooden to the touch Possible thawing (skin is soft and body part can appear gray or purple; skin tingles painfully; blisters develop within a few hours.

Cold Injury (17 of 20) Frostbite: What to do –Avoid a freeze-thaw-refreeze cycle. –Allow to thaw if more than 8 hours from help. –Keep clean and cover with dry dressing. –Elevate limb above the level of the heart.

Cold Injury (18 of 20) Frostbite: What to do (continued) –If thawing is inevitable and/or if transportation is assured, warm in water 104–108 º F for 30 to 40 minutes. –Dry carefully. –Protect from further damage. –Evacuate.

Cold Injury (19 of 20) Immersion (trench) foot –A nonfreezing cold injury caused by prolonged exposure to cold but without freezing. –Prevent by keeping feet warm and dry. –Treat by elevating the feet and exposing to air. –In severe cases, evacuate.

Cold Injury (20 of 20) Chilblains –Caused by repeated exposure of bare skin to wet, wind, and cold. –Causes red, itchy, tender, swollen skin. –Prevent by wearing gloves.

Heat Illness (1 of 7) The body balances heat loss against heat gain. Evaporation of sweat dissipates heat, but fluid and salt are also lost. Factors that can predispose one to heat illness: –Dehydration –Factors that limit the ability to sweat –Prior cardiovascular problems

Heat Illness (2 of 7) Heat exhaustion: What to look for –Inability to continue exercise or work due to symptoms –Headache, dizziness, fatigue, nausea, and vomiting –Rapid pulse –Thirst and profuse sweating –Gooseflesh, chills, and pale skin –Low blood pressure with possible fainting

Heat Illness (3 of 7) Heat exhaustion –What to do: Rest and maximize air circulation. Remove excess clothing. Wet the victim with cold water. Have victim drink fluids.

Heat Illness (4 of 7) Heat exhaustion –What to do (continued): In severe cases, add 0.25 tsp of salt and 6 tsp of sugar to 1 liter of water. If body temperature is greater than 102 º F, seek medical care.

Heat Illness (5 of 7) Heatstroke: What to look for –Headache –Drowsiness, irritability, unsteadiness, confusion, delirium, convulsions, coma –Rapid pulse –Low blood pressure –Dry or sweat-moistened hot skin –Body temperature greater than 106 º F

Heat Illness (6 of 7) Heatstroke: What to do –Remove victim from heat. –Remove clothing. –Start immediate, rapid cooling. –Stop cooling when body temperature falls to 102 º F or when mental status improves. –Monitor temperature frequently.

Heat Illness (7 of 7) Heat cramps –What to look for: Cramps in the calf, thighs, or abdomen following exercise –What to do: Stretch affected muscles. Give salted fluids. Do not give salt tablets.

Lightning Injury (1 of 4) Kills by stopping the heart and breathing. External injury and superficial and deep burns can occur.

Lightning Injury (2 of 4) Lightning safety guidelines –Avoid: Isolated tall trees, hilltops, power lines or pylons, small exposed shelters Tents Hill ridges and summits Rock walls

Lightning Injury (3 of 4) What to look for: –Loss of consciousness –Superficial steam burns –Shredded clothing or shoes that have been blown off –Blue, mottled limbs –Fractures or internal injuries

Lightning Injury (4 of 4) What to do: –Check breathing. –CPR if necessary. –Check for injuries. –Give supportive care: Maintain airway, provide shelter, monitor vital signs. –Evacuate.