Environmental Injuries

Overview

Environmental conditions and bites/stings can deteriorate quickly. For venomous bites, immobilize and evacuate—don’t cut, suck, or apply arterial tourniquets. Treat stings by recognizing anaphylaxis early and using epinephrine when indicated. Manage heat and cold injuries decisively with insulation or active cooling, and descend immediately with altitude red flags.

Skill Level: Basic–Intermediate

Snake Bites

What Not To Do

No cutting, sucking, ice, electric shocks, or alcohol. Do not apply arterial tourniquets (can worsen damage). Don’t try to catch/kill the snake.

Pressure Immobilization (where appropriate)

Used primarily for neurotoxic elapid bites (e.g., Australia; some Asian/African species). Not recommended for most North/South American pit viper bites (rattlesnakes/copperheads) due to tissue‑damage risk.

• Technique: Wrap a broad elastic bandage firmly (like a snug sprain wrap) over the entire bitten limb starting distally, then immobilize with a splint; keep patient still. Check distal circulation.
• Indications: Local protocols/species. When in doubt in elapid regions, call poison control/EMS.

Evacuation

Keep the patient calm and still; immobilize the limb at heart level; remove rings/watches; mark swelling line/time.

• Call EMS/Poison Control; transport rapidly to antivenom‑capable facility.
• Provide: Time of bite, species description/photo (only if safe), progression of swelling/pain, allergies/meds.

Insect Bites & Stings

Local Reactions

Cold compress 10–20 minutes; elevate; oral antihistamine for itching; monitor 24–48 h.

Anaphylaxis

Life‑threatening allergic reaction: hives, swelling of lips/tongue, wheeze, breathing difficulty, vomiting, dizziness, drop in blood pressure.

Antihistamines

Oral antihistamines help itching/swelling; follow label dosing. Non‑drowsy during daytime activity.

EpiPen Use

If prescribed or available for known allergy, give epinephrine at first sign of systemic reaction.

• Use auto‑injector into outer thigh (through clothing if needed). Hold 3–10 seconds (per device); massage briefly.
• Call EMS. If symptoms persist, a second dose may be needed after 5–15 minutes.

📝 Note: Typical auto‑injector dosing is 0.15 mg for children under ~30 kg (66 lb) and 0.3 mg for larger children and adults. Carry two if possible and protect from heat/cold per label.

Ticks

Prompt removal reduces risk of disease transmission.

Removal

• Use fine‑tipped tweezers to grasp the tick as close to the skin’s surface as possible.
• Pull upward with steady, even pressure; do not twist or jerk. Parts that remain usually come out with normal skin turnover.
• Do not use petroleum jelly, nail polish, heat, or other folk methods.
• After removal, clean the bite and your hands with soap and water or an alcohol‑based sanitizer.
• Save the tick (in a sealed bag/container or a clear photo) and note the date/location; this may help a clinician assess risk.

Aftercare & When to Seek Care

• Watch for a spreading rash (especially “bull’s‑eye”), fever, fatigue, joint pain, or flu‑like symptoms in the following days to weeks; seek medical care if these develop.
• In some regions, clinicians may consider antibiotic prophylaxis for certain high‑risk bites—consult a healthcare professional; do not self‑prescribe.

Hypothermia

Early: Shivering, fumbling, mild confusion. Moderate/severe: Shivering stops, slurred speech, drowsy, slow pulse.

• Passive: Dry layers, wind/water block, insulate from ground; warm, sweet drinks if alert.
• Active: Body‑to‑body heat, heat packs to armpits/groin/neck (wrap in cloth), warmed fluids if trained. Handle gently.

Hyperthermia

Heat exhaustion: Heavy sweat, weakness, nausea; cool with shade, water, evaporation, and ORS; rest.

Heat stroke (emergency): Altered mental status, very hot skin; call EMS; aggressive cooling—prefer rapid whole‑body cold‑water immersion if feasible and safe; otherwise douse with water and fan hard; ice to neck/groin/armpits.

Frostbite vs Trench Foot

Frostbite: Frozen tissue; numb, waxy, hard skin; blisters after rewarm. Rewarm only if refreezing risk is gone: warm water bath 37–39°C (98–102°F) 15–30 minutes; do not rub. Protect and pad; evacuate.

Trench foot: Cold‑wet exposure without freezing; numb, pale/mottled, painful. Dry, warm, elevate; change socks; gradual rewarm.

Altitude Sickness

AMS: Headache, nausea, poor sleep at altitude; treat with rest, hydrate, mild pain relief; do not ascend with symptoms.

HACE (brain): Ataxia, confusion; descend immediately; oxygen if available.

HAPE (lungs): Shortness of breath at rest, cough, frothy sputum; descend immediately; oxygen; minimize exertion.

Ascent rules: Climb high, sleep low; >3,000 m (10,000 ft) increase sleeping altitude ≤500 m/day; rest days every ~1,000 m.

Sun & Eye Protection

Cover skin; use wide‑brim hat; sunglasses with UV protection; apply/reapply sunscreen (SPF 30+). In snow/water, increase protection due to reflection.

☑️ Checklist — Environmental Injury Quick Actions

• Snakebite: Immobilize, pressure immobilization in elapid regions, no cutting/sucking/ice, evac
• Sting allergy: Epi for systemic signs, antihistamine, EMS
• Hypothermia: Insulate ground/back, dry layers, heat packs to core
• Hyperthermia: Shade, water, evaporative cooling, ORS; EMS if stroke signs
• Frostbite: Warm water bath if no refreeze risk; pad and protect; evac
• Altitude red flags: Ataxia or breathlessness at rest → descend now

Examples

• Desert hike: Bee stings with hives/wheeze; administer EpiPen, call EMS, second dose after 10 minutes if wheeze persists; monitor airway.
• Alpine camp: Mild AMS; rest day, hydrate, mild analgesic; postpone ascent; monitor for ataxia.

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Common Mistakes

• Cutting/sucking snakebites, applying ice, or using arterial tourniquets on pit viper bites.
• Walking a snakebite victim any distance when immobilization and evac are feasible.
• Rewarming frostbite when refreezing risk remains; rubbing or massaging frozen tissue.
• Treating anaphylaxis too late; delaying epinephrine at first systemic signs (wheeze, facial swelling, widespread hives).
• Mistaking heat stroke for exhaustion and under‑cooling; not calling EMS with altered mental status.
• Continuing ascent with AMS symptoms or delaying descent with HACE/HAPE signs.

Key Takeaways

• Immobilize and evacuate snakebites; use pressure immobilization only in appropriate regions/species.
• Treat allergic reactions early; epinephrine saves lives—use it with systemic signs.
• Prevent and reverse thermal injuries with insulation or cooling; descend immediately with altitude red flags.

Scenarios

🧭 Scenario (Regional park, snakebite): Ankle bite; triangular head, rattling nearby.
🔍 Decisions: Cut/suck vs pressure vs immobilize; move or stay; evac plan.
✅ Outcome: You immobilize, keep limb at heart level, mark swelling times, and evacuate without walking far; you call Poison Control.
🧠 Lessons: No cutting/sucking; immobilize and go
🏋️ Drill: Practice a snug pressure wrap on a partner (elapid regions).

🧭 Scenario (Bee swarm, urban): Two stings; hives spread; wheeze starts.
🔍 Decisions: Epi now or wait; antihistamine; EMS.
✅ Outcome: You give Epi promptly, call EMS, and monitor airway.
🧠 Lessons: Early Epi saves lives
🏋️ Drill: Train with an Epi trainer until it’s automatic.