2 AimTo give firefighters an overview of survival physiology and in-water survival techniques.
3 Learning Outcomes At the end of the session students will be able to: State the physiological effects of cold water immersionDemonstrate the treatment for hypothermiaDemonstrate in-water survival techniques as a single survivor and in group conditions.
4 What is survivalSurvival is the ability to stay alive when life is threatened by voluntary or involuntary immersion in water.
5 Survival factors Survival difficulties can be minimised by; The equipment availableThe action taken by the survivors or any bystanders.
6 Survival difficulties Heat lost when immersed in water is 26 times greater than the normal loss of heat when drySurvival time will depend on the protection provided, movement of the body and buildAlcohol and swimming increase the rate of heat loss.
7 Approximate survival times Survival times for a clothed person
8 LifejacketsWell-constructed life jackets can decrease heat loss rates by 40%-50%Must be able to:Hold the mouth and nose of an unconscious person clear of the waterRight them from face down in no more than 5 seconds.
9 Marine lifejackets Duncan III Lifejacket: Used for offshore firefighting tug responseBulky garments with inherent buoyancyDo not require inflation to achieve full buoyancy.
10 Marine lifejackets Crewsaver BSI 150N Lifejacket: Carried on selected appliances with an identified water risk in the station areaContain synthetic material within the garment but full buoyancy is not achieved until inflated using the oral tube.
11 Aviation lifejackets Carried by airborne response stations Only type of lifejacket acceptable for helicopter travelHave no buoyancy until inflatedMust not be inflated until clear of the aircraft.
12 Immersion hypothermia No matter how warm it is above the water, keep on wearing that life jacket!If you do end up in the water, it keeps you afloat, and helps slow heat loss from the trunk.
13 Water entry Remove any false teeth, spectacles and sharp objects Get down to less than 10 m if possibleBlock off nose and mouth with one hand brace with the other handLook down and check clear belowStand up, look straight ahead, step off.
15 Actions in the water Immersion hyperventilation is the first risk... The first few seconds of immersion in cold water bring a breathing pattern of deep, involuntary gasps (Gasp Reflex)This is followed by a minute or more of deep, rapid breaths, with tidal (breathing) volumes about five times normalDrowning can easily happen in this early stage, especially if you are plunged deep below the surface, or fall into rough water.
16 Actions in the waterHowever, most people immersed in cold water survive this initial stageIf you have the time to exercise the choice, enter cold water as gradually as possibleConsciously control your breathing, if at all possible, during entry and for the first few minutes afterward, until the feeling of not being able to catch your breath is gone.
17 Actions in the waterOnce immersed, swimming is a dangerous choice to makeAn average person who can ordinarily swim well probably will not be able to swim more than 1 km (.062 mi) in 50°F (10°C) water on a calm dayPeople who tread water lose heat about 30% faster than people holding still while wearing a life jacket.
18 Actions in the waterAny motion you make while you are in cold water takes heat away from you much more quickly than holding stillDo not swim unless you need to avoid a hazard or self rescue is easily achievedGet into the single survivor position to conserve body heatIf in a group form a huddle, any injured persons should be in the centre.
19 Actions in the waterHuddling with one or more other people will reduce heat loss rates by about a third, especially if chest to chest contact is maintained
20 Actions in the water Single Survivor Placing your hands under the life jacket and raising your knees towards your chest will reduce your heat loss rate.
21 Immersion hypothermia Knowledge of how immersion hypothermia works and being prepared will definitely help you to extend your survival time.
22 At risk situationsUnprotected immersion in water cooler than 60°-70°F (16°-21°C) places you at risk of developing hypothermiaInjured people are more likely to develop hypothermia than healthy people due to shock or other complications caused by their injuriesHypothermia can develop rapidly if you are immobilized involuntarily or voluntarily.
23 HypothermiaIn relation to hypothermia, cold water has two specific threat characteristics:Extreme thermal conductivity (the rate at which it can conduct heat away from you)The specific heat of water (the large amount of heat needed to raise water temperature)These, plus water’s ability to penetrate clothing, make immersion hypothermia a potential hazard.
24 Hypothermia Diagnosis Subject cold to touch Subject looks cold (blue) Subject may be shiveringSubject shows signs of abnormal behaviourSubject is aggressive, speech slurred.
25 Treatment The coldest part of the body is always the surface Blood that has passed under the surface during a slow re-heating will be cooledThis will further lower the core temperature, with possible fatal results
26 TreatmentRapid re-warming should not be undertaken except under medical supervisionThis may cause circulatory collapse with fatal resultsSpontaneous re-warming allows the victim to re-warm using their own body heatWrap victim in blankets and allow them to slowly re-heat using their own body heat.
27 Treatment Do not under any circumstances use foil emergency blankets This is similar to wrapping a frozen chicken in tinfoil and expecting it to defrost.
28 Visual distress signals Gun or other explosive signal (1min intervals)Continuous sounding of any fog apparatusRockets or Flares throwing red starsInternational code N.CSquare flag with ball above or belowFlames on a vesselParachute or hand flareSmoke signal (orange smoke).
29 Visual distress signals Slowly raising and lowering armsSOS in morse by radioSpoken word ‘Mayday’Radio-telegraph or radio alarm signalEPIRB
30 Means of location Nimrod Aircraft (1 hour readiness) Rescue Helicopters (15 min to 1 hour)Ships in the vicinityRNLI rescue craft.At night or poor visibility, nimrod will show green flaresSurvivors answer with red flares.
31 Confirmation State the physiological effects of cold water immersion Assessments will be based on this lesson and the corresponding study note:State the physiological effects of cold water immersionDemonstrate the treatment for hypothermiaDemonstrate in-water survival techniques as a single survivor and in group conditions.