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Evacuation, Environmental Injuries and Death at Sea

How to care for castaways and rescued people (hypothermia, cold and heat injuries, dehydration), how to confirm, record and handle a death at sea, and how to move a casualty and prepare them for helicopter evacuation. A core MCA medical subject where the wrong instinct, like rubbing frostbite, ice baths or declaring death too early, can cost a life.

Last reviewed 1 Nov 2026 · From a professional captain's years of study notes · Organised with AI and checked against current regulations · How we write

https://shipshape.wiki/articles/evacuation-environment-death-at-sea/

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Castaway Survival and Hypothermia Stages

In short: in cold water a person loses heat fast. Stage them by core temperature and signs, and treat the stage.

  • Triage: with several rescued people, start with the one most likely to survive.
  • When air temperature is below 20–21°C, survival depends on:
    • insulation: clothing and body fat
    • surface-to-volume ratio: more surface means faster cooling, so children cool faster
    • basal metabolic rate
    • will to survive
  • Seawater freezes at −2°C. At that temperature the body cools very quickly. Ungloved hands stop working in 1–5 min and consciousness is lost after 5–7 min.
  • Leaving the water drops core temperature by a further ~5°C (wind chill).

Swiss Hypothermia Classification (core temperature)

Stage Core temp Signs Treatment
Healthy 36–37°C Normal None
HT1 32–35°C Conscious, shivering Warm place, dry clothes, warm drinks
HT2 28–32°C Drowsy or confused, no longer shivering Active rewarming (heat packs, warm fluids), heart monitoring, insulate the whole body
HT3 24–28°C Unconscious As HT2 + airway control; hospital (ECMO / bypass)
HT4 under 24°C No signs of life Advanced life support, then as HT3

Shivering stops while the casualty is still cold → they are getting worse (HT1 → HT2), not better.

Swiss hypothermia stages by core temperature, HT1 to HT4
Fig. 1 — Swiss hypothermia stages by core temperature, HT1 to HT4.Diagram © Nautical Wiki

SCMG scale and treatment ladder

  • SCMG scale (core temperature, rectal thermometer): 37° normal · 36° mild · 35° moderate · 33° grave · 31–30° severe / very severe · 28° critical · 25° probably fatal.
  • The SCMG and Swiss scales use different labels. Learn both.
  • Treatment ladder as it gets worse (SCMG): dry clothes → off watch, warm sweet drinks → never left alone, buddy warming, kept horizontal → contact TMAS, recovery position → prepare to evacuate → handle gently.
  • Prevention: good food and fluids, limited time on deck, a heated space below deck, no alcohol, proper clothing (dry, gloves, face protection, loose boots, spares).

Assessment: Circulation and Disability

  • Circulation: cold hands and feet, slow capillary refill · slow pulse with possible arrhythmia · low blood pressure · look for injuries from the rescue · cold diuresis (cold makes the kidneys produce more urine).
  • Disability: agitation → confusion → coma · below 30°C pupils can be fixed and dilated, so never declare death on the pupils alone · slow, clumsy movement · blood glucose high at first, then falls.
  • Breathing can slow to ~3 breaths/min with a very slow pulse. This is a hibernation-like state, not death.
  • Terminal signs: paradoxical undressing (the casualty strips off) → curls into a fetal position → cardiac arrest.
  • Hypothermia impairs clotting, so injuries bleed more.

Hypothermia Resuscitation and Rewarming

In short: “not dead until warm and dead”. Check longer, move gently, keep CPR going while you rewarm.

  • Check longer: look, listen and feel for breathing and a pulse for up to 1 minute, not the usual 10 s. A cold pulse is slow and weak.
  • In doubt → 5 rescue breaths (once out of the water), then CPR.
  • Radio medical advice at once for any cardiac arrest in hypothermia.
  • Move gently. Rough handling triggers fatal arrhythmias.
  • CPR continues during rewarming (e.g. in a thermal protective aid).
  • AED below 30°C: only 3 shocks. A cold heart does not respond to defibrillation. After 3 failed shocks, carry on with CPR, recheck the temperature after 30 min, and shock again once it is over 30°C.
  • No CPR unless you are sure there is no pulse and no breathing. Keep supporting the casualty until they are over 32°C and still pulseless before declaring death (SCMG).

Passive rewarming step by step

  1. Position: flat. Do not raise the legs. If vomiting, turn onto the side. Some teaching material shows the legs raised 5–6 cm. The safer practice is to keep the casualty flat.
  2. Take off wet clothes and keep the casualty dry, but never undress them on open deck.
  3. Get them into a warm space.
  4. Insulate with blankets + space blanket or foil + a hat (the head loses a lot of heat).
  5. Rewarm by stage: HT1 → warm place, dry clothes, warm drinks. HT2 and worse → active rewarming (heat packs, warm fluids), heart monitoring, insulate the whole body.

Post-immersion collapse: in the water, water pressure supports the circulation. Lift the casualty out and blood pressure can crash. This is why they are kept flat and moved gently.

Cold Injuries: Chilblains, Immersion Foot and Frostbite

In short: cold injuries are non-freezing (above 0°C, cold + wet) or freezing (below 0°C). Warm and dry them, and never rub.

  • Aggravating factors: cold, wet, wind chill, sweat, drugs or alcohol, seasickness, dehydration, hunger, lack of sleep, injury (SCMG).

Non-freezing injuries

  • Chilblains (“sausage” fingers): red, itchy, tender lumps on fingers and toes, thickened skin, reduced feeling. Treat: keep warm and dry, pain relief. Take care with fine tasks, because the casualty drops things.
  • Immersion foot / trench foot: feet cold and wet for a long time (tight boots, liferaft). First pale and cold, then swollen, purple and numb. On rewarming the foot turns red and very painful. Treat: dry, warm, elevate, do not massage. Prevent with dry socks and loose boots.

Freezing injuries: depth of damage

  1. Normal skin.
  2. Frostnip: outer skin layer only (epidermis). Cold, white, painless at first (fingers, ears, nose). Reversible with simple warming. Do not rub.
  3. Superficial frostbite: epidermis + dermis. White, waxy skin that blisters on rewarming.
  4. Deep frostbite: down to the tissue under the skin. Black, dead tissue, permanent loss.
  • The deeper the freezing, the more layers are hit and the more permanent the damage. Gangrene can lead to amputation.
  • Frostbite treatment (SCMG): pain relief before rewarming (it is very painful) → 40°C water bath → sterile dressing → elevate.
  • Skin care: Vaseline keeps the skin moist, no scratching, no smoking (it narrows blood vessels).

Heat Exposure and Heat Stroke

In short: a castaway in the sun suffers burns and fluid loss. Heat illness runs from cramps to exhaustion to heat stroke, a life-threatening emergency.

  • Hours of sun without protection can cause 1st to 3rd degree burns, depending on protection, position and exposure time.
  • Keeping clothes on reduces burns. Do not look at the sun or its glare on the sea.
  • Heat illness spectrum (fluid lost in sweat, worst in the tropics): 1️⃣ heat cramps (mildest) → 2️⃣ heat exhaustion → 3️⃣ heat stroke (life-threatening).
  • Heat exhaustion = pale skin, heat stroke = red, dry skin.
  • At risk: people not used to the heat, engine-room crew, people who drink too little.
  • Heat stroke signs: rapid pulse, hot red skin with no sweating, dizziness, headache, vomiting, confusion, delirium, fits, coma, tremor or muscle rigidity, dilated pupils, a rigid posture with toes pointing down and head back.
  • Heat stroke mortality is about 20%.
  • Prevention: no alcohol, light clothing, limited time outside, sunscreen, drink enough, cool showers.

Heat stroke management

  1. DR BBCFS – ABCDE approach (Danger, Response, Breathing, Bleeding/Burns, Consciousness, Fractures, Shock). Move the casualty out of the heat.
  2. Airway and breathing: monitor the GCS, give oxygen, ventilate if needed.
  3. Cool: cold packs where large blood vessels are near the surface, at the neck, armpits and groin (and wrists). Tepid sponging works too: lukewarm water evaporates and cools without shock.
  4. Circulation: rectal infusion or IV line, fluids slowly: 1 L over 6 hours.
  5. Cooling target: 0.1°C per minute (same methods as heat exhaustion).
  6. Monitor urine output (risk of kidney failure). Cooling can trigger fits.

Hospital guidance names cold-water immersion as the fastest cooling method. On board: never ice and never an immersion bath. Use room-temperature water + wet sheets changed often + a fan.

  • 🌡️ High fever rule (SCMG 22nd ed.): any temperature 40°C or more → cool fast until below 39°C. Leave the thermometer in for 4 min. Recheck every 30 min until it has stayed below 39°C for 1 hour.

Dehydration and Malnutrition

In short: replace lost fluid slowly. Reversing dehydration or starvation too fast can kill.

  • Pinch test (skin turgor): pinch the back of the hand or forearm. Skin that stays “tented” and falls back slowly = dehydrated. Skin that snaps back = fine.
  • Other signs: thirst, dry mouth and lips, dark, scanty urine, sunken eyes, hollow cheeks, dry, cracked tongue, tiredness, dizziness, confusion (severe).
  • Management: replace the fluid lost while adrift, with caution. The same applies to malnutrition.
    • A sudden reversal shifts fluid out of the circulation → oedema → brain swelling and coma.
    • Start with oral rehydration salts (ORS) and fluids slowly, or IV fluids.
    • Target: urine output about 1 L/day. This target is urine, not water drunk.
    • Radio medical advice (TMAS) every time.
  • Dehydrated more than 48 h → rehydrate with great caution. Even under 48 h → small amounts at a time.
  • Homemade electrolyte drink: about ½ tsp sea salt per 1.5 L water + sugar + lemon. It “should taste like tears”.
  • Liferaft water: 1 L per person per day, nothing in the first 24 h.
  • Seasickness link: persistent vomiting → loss of potassium and calcium → heart rhythm risk. Give small sips, or fluid per rectum if nothing stays down.
  • Ketones in the urine show up in starvation as well as in diabetes.

Drinking too much too fast can kill (electrolyte imbalance, low sodium).

Death at Sea: Confirming, Recording and Handling the Body

In short: confirm death carefully and never alone. Record everything with a witness, and keep the body and property intact for the inquiry (SCMG, non-survivor / life extinct).

Signs and timeline

  • Death = all the biological functions that keep the body alive have stopped.
  • Pallor: immediate.
  • Livor mortis: blood settles by gravity in the lowest parts → purple-red patches, with pale pressure areas where the body rests. It starts ~30 min after circulation stops and is visible at ~2 h.
  • Rigor mortis: muscles stiffen from ~4 h, then the stiffness slowly passes off.
  • Putrefaction: after hours to days. Heat speeds it up.
  • These stages help estimate the time of death.

Confirming death

  • Never alone. In hospital three people check.
  • Pupils dilated and not reacting to light.
  • No breathing for a full 1 min. Hypothermia and drugs can mimic death.
  • Stethoscope on the apex of the heart for a full 2 min.
  • Bedside tests (SCMG 22nd ed.):
    • 🪞 Mirror at the nose and mouth: it mists if the person is alive.
    • 🧵 String tied round a finger: the tip turns blue if alive and stays white in death.
    • 💅 Nail pressure: colour comes back after blanching if alive.
  • 🛑 Stop CPR only when the radio medical doctor says so, or when you are physically exhausted.

Below 30°C, fixed dilated pupils and near-absent vital signs can mimic death. The casualty is “not dead until warm and dead”.

  • Document and sign every event leading to the death. This builds the picture of the cause. Keep the records safe for any later inquiry.
  • Record what happened and how the injury or illness came about. A medico-legal inquiry may follow even when no foul play is suspected.
  • 📓 Official Log Book: make the correct entries (the relevant section is at the back).
  • Record everything with a witness, take photographs, follow the SCMG.
  • Give correct information to the Port Authorities.
  • Property: list it and log it, and keep it in safe custody.
  • Body: store it correctly.
  • Crew: watch the effect on the ship’s company. Debrief the crew as if they were casualties too, and take statements if needed.

Handling the body

  • 🧊 Body bag + fridge or freezer only if the doctor or authorities advise it. If heat forces you to do it anyway, record the time and temperature, because this matters at the autopsy.
  • 🚿 Leave the body intact: stop a running drip but leave all lines and tubes in place. If the body is soiled → photograph first, document, then clean.
  • 🌊 Body found at sea: inform the authorities, mark the position, take photos and stay in range until the coastguard recovers it.
  • 👕 In hospital the body is dressed within ~1 h, before rigor sets in.

Care of the dying

  • There is never a stage when nothing can be done.
  • Protect the patient from suffering and pain, keep people with them, and protect their dignity throughout.
  • 📝 Last wishes: write them down with 1–2 witnesses. An unwitnessed note can be contested.
  • 🍽️ Do not force food or drink. Give it only if asked. Keep the patient clean, warm, comfortable and in a quiet place.

Moving the Casualty

In short: make the boat steady, plan the route, then move slowly with enough people and the right stretcher.

  • ⛵ Stabilise the boat first: choose the course and trim with the least movement before any procedure, such as an IV, suturing or immobilisation.
  • 🗺️ Plan the route before moving a stretcher. Get enough people, and tell the crew and the casualty what will happen.
  • Move slowly. A hypothermic casualty moves very slowly, because rough handling causes arrhythmia.
  • 🙌 No equipment → two-person lift: one rescuer behind, supporting the head, neck and chest, and one under the thighs. Bend at the knees and lift on a clear command.
  • Blanket lift: fine for an arm injury, NOT for a spinal injury (that needs 6 people and a tight blanket).
  • 🦶 Suspected spinal injury: tie the feet and ankles with a figure-of-eight bandage, then apply gentle traction on the head and feet to straighten the body. Never fold the casualty. There is no rush to move.
  • Stretcher: it must be rigid (Neil Robertson or basket). Plain canvas only if stiffened with cross boards.
  • 🚶 Narrow spaces: fore-and-aft carry (one helper under the arms, one under the knees). Last resort: a single-rescuer drag with the casualty’s wrists tied, taking care of the rescuer’s breathing apparatus.

Helicopter Evacuation

In short: get radio medical advice, prepare the casualty and their paperwork, and prepare the vessel as set out in IAMSAR Vol. III.

  • The hypothermia ladder ends in evacuation: contact TMAS → prepare to evacuate → handle gently.

Preparing the casualty

  1. 🛍️ Evacuation bag: passport, ID, wallet and cards, personal medicines, 1–2 changes of underwear + 1 of clothing, toiletries, a photocopy of all on-board medical records.
  2. 📄 Medical records + passport in a plastic envelope, which goes with the casualty (SCMG 22nd ed.).
  3. 💉 Tag the casualty if morphine was given (SCMG 22nd ed.).
  4. 🧥 Dress the casualty warmly and wrap them in a light blanket (warmth and privacy).
  5. 🦺 Lifejacket ON before they go into the stretcher (SCMG 22nd ed.).

Memory hook: envelope · morphine tag · lifejacket. These are the three things examiners ask about.

Preparing the vessel

  • Report position, course and speed.
  • Clear the deck of loose and dangerous objects.
  • Radar off.
  • Deck lighting (illumination).
  • Wind about 30° on the port bow.
  • Have a portable radio ready for the deck party.
  • The procedure is in IAMSAR Vol. III. Follow the helicopter crew’s instructions.
A casualty strapped in a stretcher is hoisted from a vessel into a US Navy helicopter during a medical evacuation. U.S
Fig. 2 — A casualty strapped in a stretcher is hoisted from a vessel into a US Navy helicopter during a medical evacuation. U.S.Photo: Navy — Public domain, Wikimedia Commons

⚡ Flashcards

Test yourself, one card at a time
  1. Q1Several people are pulled from cold water at once. Who do you treat first?
    Answer

    The one most likely to survive.

    Common trap

    Trap: starting with the worst-looking casualty, who may already be beyond help.

  2. Q2A cold casualty stops shivering. Better or worse?
    Answer

    Worse: HT1 (32–35°C, shivering) has become HT2 (28–32°C, no shivering, drowsy) (Swiss staging).

    Common trap

    Trap: reading “no more shivering” as recovery.

  3. Q3A hypothermic casualty looks lifeless. What changes in basic life support?
    Answer

    Check breathing and pulse for up to 1 min (not 10 s). In doubt: 5 rescue breaths, then CPR while rewarming. AED below 30°C: 3 shocks max, retry when over 30°C.

    Common trap

    Trap: rough handling. A cold heart fibrillates easily.

  4. Q4How do you position and rewarm a rescued hypothermic casualty?
    Answer

    Flat (on the side if vomiting), out of wet clothes below deck, blankets + space blanket + hat. Watch for post-immersion collapse.

    Common trap

    Trap: undressing on open deck. Leaving the water already drops core temperature about 5°C.

  5. Q5Frostbite on board: what is the treatment?
    Answer

    Pain relief first, then a 40°C water bath, sterile dressing, elevate (SCMG).

    Common trap

    Trap: rubbing or massaging the frozen part.

  6. Q6Heat exhaustion or heat stroke: how do you tell, and how do you cool?
    Answer

    Exhaustion = pale, sweaty. Stroke = hot, red, dry skin, confusion, fits. Cool with room-temperature water, wet sheets changed often and a fan, aiming for 0.1°C/min.

    Common trap

    Trap: ice or an immersion bath on board.

  7. Q7A castaway has been adrift for days. How do you rehydrate?
    Answer

    Small amounts, slowly (ORS), and get radio medical advice. Target = urine output about 1 L/day.

    Common trap

    Trap: letting them drink as much as they want. Too much too fast can kill (low sodium, brain swelling).

  8. Q8How do you confirm death on board?
    Answer

    Never alone: pupils fixed and dilated, no breathing for a full 1 min, no heart sounds for a full 2 min at the apex. Bedside checks: mirror, string round a finger, nail pressure (SCMG 22nd ed.).

    Common trap

    Trap: declaring a cold casualty dead. They are “not dead until warm and dead”.

  9. Q9After a death at sea, what must the Master record and do?
    Answer

    Everything with a witness and photos, logged in the Official Log Book; property listed and logged; correct body storage; correct report to the Port Authorities.

    Common trap

    Trap: cleaning the body or removing lines before photographing and documenting.

  10. Q10What do you do before you move a stretcher casualty?
    Answer

    Stabilise the boat, plan the route, get enough people, tell the crew and the casualty, use a rigid stretcher for a suspected spine injury.

    Common trap

    Trap: a blanket lift for a suspected spine injury.

  11. Q11Name the three things that go up with a casualty in a helicopter evacuation.
    Answer

    Plastic envelope (medical records + passport), morphine tag if morphine was given, lifejacket ON before the stretcher (SCMG 22nd ed.).

    Common trap

    Trap: forgetting to tag a casualty who has had morphine.

  12. Q12How do you prepare the vessel for a helicopter?
    Answer

    Report position, course and speed; clear loose and dangerous objects; radar off; deck lighting; wind about 30° on the port bow; portable radio ready (IAMSAR Vol. III).

    Common trap

    Trap: choosing your own course. The helicopter crew decides the approach.

📚 Resources

Video

Books

  • The Ship Captain’s Medical Guide, 24th edition (2024), MCA / TSO: hypothermia, cold injuries, heat illness, care of the dying and life extinct, medical evacuation. Announced in MIN 718 (M+F)

Regulations

  • IAMSAR Vol. III: Mobile Facilities, carried on board; helicopter operations with ships
  • MIN 718 (M+F): The Ship Captain’s Medical Guide, 24th edition

Official sites

Exam focus — MCA

Typical questions and what the examiner wants to hear

  • “You recover a survivor from cold water. What do you do?” → Handle gently, keep them flat, check breathing and pulse for up to 1 min, take them below before undressing, insulate (including a hat), rewarm by stage, get radio medical advice, and watch for post-immersion collapse.
  • “When is a hypothermic casualty dead?” → “Not dead until warm and dead”. Do not trust fixed pupils below 30°C, support until over 32°C, AED 3 shocks max below 30°C, stop CPR only on the doctor’s advice.
  • “Heat stroke on board: how do you cool?” → Out of the heat, ABCDE, oxygen, cool the neck, armpits and groin with room-temperature water, wet sheets and a fan (no ice), slow fluids 1 L over 6 h, watch urine output and fits.
  • “A crew member dies on board. What are the Master’s duties?” → Confirm death with a witness, record and photograph everything, Official Log Book entries, list the property, store the body as advised, inform the Port Authorities, look after the crew.
  • “Prepare a casualty and the vessel for a helicopter.” → Envelope with records and passport, morphine tag, lifejacket on, warm clothing, evacuation bag. Vessel: report position, course and speed, clear deck, radar off, lights, wind 30° on the port bow, IAMSAR Vol. III.

Study material only: not legal advice and not a substitute for the official MCA, Transport Malta, IMO or flag-state texts.