Environmental emergencies arise from exposure to extreme temperatures, weather, altitude, or water. Recognizing the progression from mild to life-threatening stages and initiating appropriate first aid is critical.
Heat-Related Illness
Heat-related illness exists on a spectrum from heat cramps to heat exhaustion to heat stroke. Progression can be rapid, especially during exercise in hot, humid conditions.
Heat Cramps
Painful muscle spasms occurring during or after intense exercise in heat. Usually affect calves, thighs, arms, and abdominal muscles. Caused by electrolyte depletion and dehydration.
First aid. Move to a cool area. Rest and hydrate with water or an electrolyte sports drink. Gently stretch and massage the affected muscles. Avoid salt tablets — they can cause gastric irritation. Resume activity only after cramps resolve.
Heat Exhaustion
A moderate heat illness resulting from water and/or sodium depletion. Symptoms: heavy sweating, pale/cool/clammy skin, weakness or fatigue, dizziness, headache, nausea or vomiting, fast weak pulse, normal or slightly elevated temperature (below 104°F / 40°C), and dark urine (dehydration).
First aid. Move the person to a cool or shaded area. Remove excess clothing. Lay the person on their back with legs elevated 6-12 inches (if no vomiting). Cool the body with wet cloths, fanning, or spray mist. Have the person drink cool water or sports drinks slowly (if conscious and able to swallow). If the person vomits repeatedly, refuses fluids, or does not improve within 30 minutes, seek medical attention. Untreated heat exhaustion can progress to heat stroke.
Heat Stroke — Medical Emergency
Heat stroke is the most severe heat illness — a life-threatening emergency where the body’s temperature regulation fails, causing core temperature to rise above 104°F (40°C). The body stops sweating (red, hot, dry skin in classic heat stroke; may still be sweaty in exertional heat stroke). Altered mental status: confusion, agitation, slurred speech, hallucinations, loss of consciousness. Seizures may occur. Rapid, strong pulse followed by weak pulse as circulation fails. Breathing may be rapid and shallow.
Risk Factors for Heat Illness
Extreme heat index (high temperature plus high humidity), lack of air conditioning, obesity, dehydration, alcohol or drug use, certain medications (antihistamines, diuretics, beta-blockers, antipsychotics), chronic medical conditions (heart disease, diabetes, respiratory disease), age extremes (infants and elderly), and strenuous outdoor activity in heat.
Cold-Related Illness
Hypothermia
Hypothermia occurs when core body temperature falls below 95°F (35°C). It is classified as mild (90-95°F), moderate (82-90°F), or severe (below 82°F).
Mild hypothermia. Shivering (the body’s attempt to generate heat), cold and pale skin, numbness in extremities, poor coordination stumbling hands, slurred speech, apathy or confusion, increased heart rate and breathing.
Moderate hypothermia. Shivering stops (as shivering mechanism fails), decreasing level of consciousness, dilated pupils, slow heart rate and breathing, muscle rigidity, blood pressure drops.
Severe hypothermia. Unconsciousness, no detectable pulse or breathing (the person may appear dead), pupils fixed and dilated, rigid body.
First aid for hypothermia. Move the person to a warm environment. Remove wet clothing and replace with dry layers. Warm the person gradually — use blankets, warm (not hot) water bottles wrapped in cloth placed in the armpits, groin, and neck. Share body heat (skin-to-skin contact under dry blankets). Give warm sweet beverages if the person is conscious and able to swallow. Do NOT give alcohol or caffeine. Do NOT rub the arms and legs (this causes vasodilation and drops core temperature further). Do NOT use direct heat (hot water, heating pads directly on skin) — this can cause burns and dangerous cardiac arrhythmias. The person should be rewarmed slowly. Handle a hypothermic person gently — rough movement can trigger ventricular fibrillation.
CPR in hypothermia. If the person is unconscious and not breathing, check for a pulse for 30-60 seconds (the pulse may be very slow and difficult to detect in severe hypothermia). If no pulse, start CPR. In severe hypothermia, the brain can survive prolonged periods without oxygen — continue CPR until the person is rewarmed in the hospital. “You are not dead until you are warm and dead.”
Frostbite
Frostbite is the freezing of body tissues, most commonly affecting the fingers, toes, nose, ears, and cheeks. It is classified as superficial (first-degree) or deep (second-to fourth-degree).
Superficial frostbite. White, waxy, or grayish-yellow skin; numbness; the skin feels hard but the tissue beneath is still soft; after rewarming: redness, swelling, stinging, burning.
Deep frostbite. Hard, cold, numb skin that does not blanch (turn white when pressed); blisters (clear or blood-filled) may develop; skin turns dark purple or black as gangrene develops; complete tissue loss may occur.
First aid for frostbite. Move to a warm environment. Immerse the affected area in warm (not hot) water — 99-104°F (37-40°C). Warm water that feels comfortably warm to normal skin. If warm water is not available, use body heat (place frostbitten fingers in the armpit). Rewarming takes 15-30 minutes and is extremely painful — give ibuprofen or acetaminophen for pain. After rewarming, the skin should be pink and sensation should return. Loosely cover the area with sterile gauze. Elevate the affected extremity to reduce swelling.
Do NOT. Rub or massage frostbitten tissue (causes further damage from ice crystal formation). Use direct heat (hair dryer, heating pad, stove, fireplace) — the numb tissue cannot feel the heat and will burn. Break blisters. Rewarm if there is a risk of refreezing before reaching medical care (freeze-thaw-freeze causes more damage). Walk on frostbitten feet unless absolutely necessary (walking on thawed feet causes severe damage).
Altitude Sickness
Acute mountain sickness occurs when ascending to high altitude (above 8,000 feet / 2,400 meters) too quickly without adequate acclimatization. Symptoms appear 6-12 hours after arrival: headache (the cardinal symptom), nausea or vomiting, fatigue, dizziness, difficulty sleeping.
High altitude cerebral edema (HACE). A life-threatening progression of AMS: severe headache that does not respond to painkillers, ataxia (loss of coordination — cannot walk a straight line), confusion, hallucinations, loss of consciousness.
High altitude pulmonary edema (HAPE). Fluid in the lungs: shortness of breath at rest, cough (initially dry, then producing frothy pink sputum), chest tightness, crackles (rales) heard in the lungs.
Treatment. Stop ascending — descend immediately if symptoms of HACE or HAPE are present. Descend at least 1,000-3,000 feet (300-900 meters). Supplemental oxygen (if available). Acetazolamide (Diamox) for AMS prevention and treatment. Nifedipine or phosphodiesterase inhibitors for HAPE. Dexamethasone for HACE. Portable hyperbaric chamber (Gamow bag) can simulate descent. The definitive treatment for severe altitude illness is descent.
Lightning Strike
Lightning injuries range from minor burns to cardiac arrest. Lightning causes cardiac arrest (the main cause of death from lightning strike), neurologic damage (temporary paralysis, confusion, memory loss, keraunoparalysis — temporary paralysis of the lower extremities), burns (linear, feathering, or punctate), and blunt trauma (from muscle contractions or being thrown).
First Aid
Lightning strike victims do not carry an electrical charge — it is safe to touch them immediately after the strike. Activate EMS. Assess and treat cardiac arrest first — lightning victims with cardiac arrest have a good chance of survival with immediate CPR (the heart may spontaneously resume normal rhythm if the brain has been oxygenated). Triage rule: treat the apparently dead first (in most mass casualty events, you help the conscious first, but in lightning strikes, those who appear dead may have reversible cardiac arrest). Treat burns as thermal burns. Immobilize the cervical spine if there is suspicion of a fall or blast injury.
Lightning Safety
When thunder is heard, the lightning is close enough to strike. Seek shelter in a substantial building or enclosed metal-topped vehicle. Avoid open fields, hilltops, tall isolated trees, bodies of water, and metal objects (fences, umbrellas, golf clubs). Wait 30 minutes after the last thunderclap before resuming outdoor activities.
Drowning
Drowning is respiratory impairment from submersion or immersion in liquid. It is a leading cause of unintentional injury death worldwide, especially among children. Drowning can be fatal (death) or non-fatal (survival with or without sequelae).
The Drowning Process
The drowning person cannot call for help — the airway instinctively seals to prevent water entry. The arms are at the sides, pushing down on the water (the instinctive drowning response). The head is tilted back with the mouth at the water surface. The person is vertical in the water, not kicking. Survival time is typically 20-60 seconds before submersion.
Rescue
Reach or throw, do not go (unless trained). Use a pole, branch, towel, or reaching device from a safe position. Throw a flotation device or rope. If entering the water is necessary, approach from behind the person (a panicking person can pull the rescuer underwater). Bring the person to shore or the boat. Assess consciousness and breathing immediately.
First Aid
Unconscious and not breathing: start CPR immediately — give 2 rescue breaths followed by 30 chest compressions. Rescue breaths are especially important in drowning (the primary problem is hypoxia from water in the airway). Do not attempt to drain water from the lungs (Heimlich maneuver for drowning is not recommended — it delays ventilation and may cause vomiting). Remove wet clothing and cover with dry blankets to prevent hypothermia. All drowning victims, even those who appear fine after rescue, should be evaluated in an emergency department (risk of secondary drowning — pulmonary edema developing hours after the event).
Prevention
Never swim alone. Supervise children constantly near water (touch-supervision — an adult should be within arm’s reach). Install pool fencing with self-latching gates. Learn CPR. Wear life jackets on boats and in open water. Learn to swim. Do not mix alcohol and swimming or boating.
Summary
Environmental emergencies require recognition of progression from mild to severe. Heat cramps and heat exhaustion can be managed with cooling and hydration; heat stroke is a medical emergency requiring aggressive cooling. Hypothermia requires gradual rewarming and gentle handling; severe hypothermia has excellent outcomes with continued CPR. Frostbite requires warm-water immersion — never rub or use direct heat. Altitude sickness is treated by descent. Lightning strike victims should receive immediate CPR. Drowning prevention is critical, and rescue breaths are a priority in drowning resuscitation.