The Huddle Technique Even though it may be t-shirt weather and the air is warm, the water canstill be very cold. Because the majority of us do not participate in cold water activities, we are unaware of how our bodies react in early and late season conditions. On average, 200 people die each year from cold water immersion. If you're heading out on the water this winter, or even doing some work around the shoreline, there are a few things that you should know about Cold Water Immersion and Hypothermia. Important StepsIt is important to keep your head out of the water. A large percentage of your body heat is lost through your head, so it is critical to keep dry. Cold temperatures significantly decrease your physical ability. Swimming will be more difficult and you will not be able to swim as far. H.E.L.P.Heat EscapeLessening Position Always try to remove yourself from the cold water if you happen to fall in. If you have fallen from a boat, attempt to climb back on board. If you are a confident swimmer and a reasonable distance from shore, and suspect that rescue may not be likely, you may attempt to swim. But remember, you will not be able to swim as far in cold water. Floating in the H.E.L.P. (Heat Escape Lessening Position) will significantly increase survival time. Be sure you know how and practice this position. You want to keep as much body heat as possible from escaping. If you are alone, cross your arms tightly against the chest and bring your knees up close to the chest. If there are 3 or more people, huddling in a group is the best option. When you are rescued, be sure to replace wet clothing with dry and remain in a warm setting until you are confident that your core body temperature is back to normal. The Stages of Cold Water ImmersionIf a person falls into cold water - their body's initial reaction is a 'gasp reflex' which can include hyperventilation and muscle spasms. This initial reaction can result in water inhalation as well as significant changes in heart rate and blood pressure. These initial effects are present for the first two or three minutes of immersion.
Even if you don't spend a lot of time boating or fishing you still need to be prepared for an accidental immersion into cold water. When you first hit the water you may be in shock. It's important to regain composure as quickly as possible so you are able to assess your surroundings and formulate a plan to reach safety. Swim, paddle, move - don't just float. Research suggests people can swim in cold water for a distance ranging between 800 and 1500 meters before being incapacitated by the cold. If possible, try to swim towards safety. Make a decision to act early If you fall into cold water, try to remain calm and assess your surroundings. The sooner you can devise a plan to get to safety, the better. During a study of cold water immersion, 86% of subjects who acted quickly were successful in completing their self-rescue plan. After thirty minutes, those who hesitated experienced impairment in their decision-making abilities. Do not panic - you have time Adults require 30 minutes or more to become clinically hypothermic, and 1 hour or more to become severely hypothermic. This gives you the time you need to ensure your life jacket is securely fastened and formulate a plan to reach safety. Keep your head up Immersion in to cold water can cause sudden disappearance syndrome. This usually occurs when the water temperature is below 15.5°C (60°F). When you initially hit the water you may experience gasping, profound hyperventilation, and cardiac arrhythmias. If your head is under water when you gasp, you may inhale water and drown. Get out of the water quickly and seek immediate medical care. Get warm There are over 14 rewarming treatments which have successfully been used to rewarm an individuals with hypothermia. For more information on water safety, contact your local Aquatics program.
Cold Water Shock is a real danger in water below 15°C. If you do find yourself in the water, a lifejacket could literally save your life. Cold Water Shock is a cause of death that many people fail to appreciate. Adequate clothing and a lifejacket will potentially help you to survive long enough to be recovered. When the body is suddenly immersed in cold water it experiences a number of physiological responses that can rapidly incapacitate and even kill. The sudden lowering of skin temperature is one of the most profound stimuli that the body can encounter. The biggest danger is inhaling water and drowning, even if the water is flat, calm and you know how to swim. Cold Water Shock causes an immediate loss of breathing control. You take one or more huge gasps, followed by hyperventilation – very rapid breathing that is hard or impossible for you to control. As blood vessels contract, increases in heart rate and blood pressure may result in cardiac arrest even in people who are in good health. At the same time a “gasp” response may result in water being inhaled into the lungs and your breathing rate may increase by as much as tenfold. The condition causes involuntary body reactions that can be as swift as they are deadly – and the ability to swim well has no impact on these responses. It is far deadlier than Hypothermia, yet far less understood by boaters in general. Hypothermia kills over time as heat is conducted away from the body leading to a gradual decline in body core temperature and loss of swimming ability, unconsciousness and ultimately death. Conversely, most people who are susceptible to Cold Water Shock die in the first minute of immersion. In the majority of cases, victims aren’t stupid or intentionally reckless, and many are strong swimmers. They simply have the misfortune of getting caught in an exceptionally lethal trap. Cold water preys on the unsuspecting and the careless, but it also waits patiently offshore for those with plenty of experience but who don’t take it seriously. What happens? Sudden cold water immersion drastically reduces your ability to hold your breath typically from a minute or so to less than 10 seconds, whilst cold water in your ears can cause vertigo and disorientation. At a water temperature below 15°C, and if you are not wearing a life jacket, especially an automatic one, cold water shock will:
Cold Water Shock is a danger in water below 15°C; that’s more or less the summertime average around the coast of the UK. It is therefore important to think carefully about the clothing you wear and protection from the cold – a dry suit will provide additional protection, particularly in very cold water. Coupled with the shock of going over the side, the condition may well contribute to a feeling of panic as you struggle to stay afloat; this will be far easier to overcome if you are wearing a correctly fitting lifejacket. A very real risk Last year saw a dog owner fall victim to Cold Water Shock after diving into the sea from his boat in an attempt to rescue his pet. The 59-year-old was spotted in the water by two jet-ski riders near Brightlingsea in Essex. The man’s son had reportedly tied a rope around his father to prevent him from becoming fully submerged in the water. Emergency services, including an air ambulance and coastguard helicopter, were scrambled to the scene. The casualty was rushed to hospital in a critical condition, but despite having been rescued after just ten minutes, he was sadly declared dead several hours later. What to do The RNLI’s advice is to float for around 60 to 90 seconds – the time it takes for the effects of the cold shock to pass and for you to regain control of your breathing. The recommended floating position is to lean back in the water and keep your airway clear while keeping calm to maintain breathing levels. You should then be in a better position to attempt to swim to safety, or call for help. The key to surviving cold shock is being alert to the symptoms and acting quickly to protect your airway and conserve your strength. If you ever recover someone from the water, they may seem okay, but may well be susceptible to secondary drowning where any water entering the lungs can cause a condition called pulmonary oedema. This can happen within 1 to 24 hours after an incident in the water. Symptoms to look out for are coughing, chest pain, troubled breathing, tiredness and irritability. A close eye may need to be kept on the person after an incident in case of these delayed symptoms. The RYA advises all boaters to think about the temperature of the water, make sure you are wearing a lifejacket, unless you have assessed it is definitely safe not to do so, and clip on your ISO approved safety line when the situation and weather dictate it. Know your limits Most people unfamiliar with cold water find 21C to be quite cold. On the other hand, a competitive open-water swimmer who is used to swimming in 13C water, will probably think that 21C doesn’t feel very cold at all. What’s important to your safety is how you personally respond to cold water. For more guidance on the risks of Cold Water Shock, contact the RYA Cruising Team on 023 8060 4233 for your free copy of the latest Safety Advisory Notice. More information on looking after yourself can also be found at www.rya.org.uk/go/safety Why not try a one-day RYA Sea Survival course? It will show you how to make the best use of liferafts and the equipment they contain. You'll also pick up survival techniques, top tips on the medical aspects of sea survival, as well as an in-depth knowledge of search and rescue techniques. Visit www.rya.org.uk/go/seasurvival Our thanks go to the National Center for Cold Water Safety (www.coldwatersafety.org), the RNLI and Mike Tipton MBE, the Professor of Human & Applied Physiology at the Extreme Environments Laboratory, School of Sport, Health & Exercise Science at the University of Portsmouth, for their contributions. |