Environmental Emergencies

How the body loses heat

The body loses heat by five mechanisms, and each one is a route you can close off when you care for a cold patient. The table below describes them.

Table 35.1How the body loses heat

Generalized hypothermia — the key decision point

The single question that guides the care of generalized hypothermia is whether the patient has an altered mental status. A patient who is alert and responding appropriately has mild hypothermia, and active rewarming is acceptable. A patient who is unresponsive or not responding appropriately has severe hypothermia, and only passive rewarming is used.

Shivering is present at temperatures above about 90°F. If shivering is absent, assume severe hypothermia. Factors that predispose a patient to hypothermia include shock, burns, alcohol or drugs, lying on cold ground, and being very old or very young.

Care — mild vs. severe

For the alert patient who is responding appropriately, active rewarming is allowed. Remove wet clothing, handle the patient gently, and do not let the patient walk or massage the extremities. Rewarm actively during transport with heat packs or warm air, but rewarm slowly. Central rewarming means applying heat to the lateral chest, neck, armpits and groin first, never to the limbs first, because warming the limbs first can send cold blood recirculating to the core and trigger shock.

For the unresponsive patient with severe hypothermia, rewarming is passive only. Open the airway, give high-concentration O2, warmed and humidified if available, and wrap the patient in blankets. Handle the patient gently, because rough handling can trigger V-fib. Give no food or drink, do not massage the limbs, and transport immediately.

In extreme hypothermia, check the carotid pulse for at least 60 seconds before declaring that there is no pulse. "You're not dead until you're warm and dead": the hospital will not pronounce death until the patient has been rewarmed and resuscitated.

Local cold injuries — frostnip vs. frostbite

Local cold injury ranges from frostnip, a minor injury, to frostbite, which reaches deeper tissue. The table below contrasts the two in the tissue involved, the appearance of the skin, and the care given.

Table 35.2Local cold injuries — frostnip vs. frostbite

Whatever the depth of the injury, never rub the area, rub snow on it, break blisters, massage it, or let the patient walk on it.

Heat exhaustion vs. heat stroke — skin is the key distinguisher

Heat exhaustion and heat stroke are distinguished above all by the skin. The table below compares the two conditions in skin findings, mechanism, signs and care.

Table 35.3Heat exhaustion vs. heat stroke — skin is the key distinguisher

Hot skin that is moist rather than dry does not rule out heat stroke. Once altered mental status and hot skin are both present, the diagnosis is heat stroke, not heat exhaustion.

Drowning

Drowning is respiratory impairment from submersion or immersion. About 10% of victims die purely from spasm of the airway, with no water aspirated. Cold water, below 70°F, can delay biological death, so resuscitation is attempted even after an arrest of 30 minutes or more.

Rescue breathing should begin in the water if the patient can be reached there, and rescue breathing or CPR begins on land as soon as the patient is out. Suspect a C-spine injury only in water accidents with a trauma mechanism, such as diving or a strike by a boat or water ski. Simple immersion drowning without trauma rarely causes spinal injury, and in that case ventilation must not be delayed for immobilization.

Scuba accidents

Two distinct emergencies follow a scuba dive, and they differ in cause, timing and presentation even though the field care is the same. The table below compares air embolism (AGE) with decompression sickness, "the bends."

Table 35.4Scuba accidents

Water rescue order & high-altitude illness

Water rescue follows a fixed order: Reach, Throw/Tow, Row, Go. Entering the water is the last resort, reserved for a rescuer who is trained and a strong swimmer, because untrained rescuers become patients.

Three illnesses occur at altitude: acute mountain sickness (AMS), high-altitude cerebral edema (HACE) and high-altitude pulmonary edema (HAPE). The table below sets out the key signs and the care of each.

Table 35.5Water rescue order & high-altitude illness

Insects, spiders & scorpions

About 5% of the population has an allergic reaction to stings, and the risk of anaphylaxis is the main concern for the EMT. Treat the patient for shock even in the absence of signs. Remove the stinger and venom sac quickly; the method matters less than the speed. Remove jewelry from the affected limb, and immobilize the limb.

Snakebites

Roughly 50,000 snakebites occur in the US each year. About 8,000 or more of them are from venomous species, yet fewer than 10 people die each year; more US deaths come from bee and wasp stings than from snakebites. Even so, treat all bites from unidentified or venomous species as serious. Locate the fang marks, remove constricting items, and immobilize the bitten extremity, but do not elevate it above the level of the heart. Never apply ice or a cold pack, cut and suction the wound, squeeze the site, or attempt to suck the venom out by mouth.

Marine life

The sting of a jellyfish or Portuguese man-of-war is rinsed with vinegar, kept out of the mouth and eyes, and then treated with nonscalding hot water to reduce the pain. A puncture from a stingray or sea urchin is soaked in nonscalding hot water for 30–90 min, but the soak must not delay transport.