Hypothermia

Riding a personal watercraft is lots of fun. Sometimes you are having so much fun you don't notice the passage of time. The action of wind and water on your skin can, over time, drastically reduce your body temperature. This reduction in body temperature is called "hypothermia." One of the early symptoms of hypothermia is shivering. Once shivering begins, you must head in to shore and get rested and warmed up before re-entering the water. If this vital signal from your body is ignored, other progressively dangerous symptoms develop. Hypothermia can be fatal if it is not dealt with in its early stages. Exposure to water - even with a temperature as high as 75° - for one hour can result in early stages of hypothermia. The waters of the northern states can be extremely cold - frequently below 50°. The colder the water, the greater the risk to the unprepared person. A swimmer has a 50% chance of swimming 50 yards in 50° water before being overcome by hypothermia. In water, the body loses heat 23% faster than on land. Nearly 90% of boating fatalities are due to drowning and nearly half of those are attributed to the effects of immersion in cold water. Wearing wet or dry suits helps keep the body's core from losing heat. If your PWC is disabled, stay out of the water and on top of your boat.

Should an immersion occur, try to get out of the water as quickly as possible. Do not try to remove clothing or shoes. Air trapped between layers of clothing will aid, not hinder in keeping a person afloat and also protect from direct exposure to cold water.

H.E.L.P. Position (Heat Escape Lessening Position)

If you have fallen off your PWC and are unable to re-board, hypothermia is a definite threat. In this situation you must resist flailing in the water. Try instead to maintain the H.E.L.P. position, as shown to the right, as you float in the water. This will help to retain the warmth in your body's central core. A rider and passengers should do what they can to get out of the water since a person in the water looses body temperature much faster, which reduces survival time.

Surviving a Cold-Water Accident

1. Stay calm. Don't panic. Try to get control of your breathing. Hold onto something floating or stay still as possible until your breathing slows down. Focus yourself on floating with your head above water until the cold shock response abates.

2. When your breathing is under control, perform the most important functions first before you lose dexterity and feeling in your fingers (10-15 minutes after immersion).

3. If you were not wearing a PFD when you entered the water, look for one floating close by and put it on immediately. Don't take your clothes off unless absolutely necessary, as this wastes precious time and energy.

4. Focus on locating and getting everyone out of the water quickly while you and others have full or near full use of hands, arms, and legs. Try to get back onboard your vessel, even if it is swamped or capsized, or anything else that is floating. Get as much of your body out of the water as possible. Even though you may feel colder out of the water, the rate of body heat loss will be slower than if immersed in water.

5. In as little as 10 minutes, you may be unable to perform a self-rescue. Your focus should now be to slow body heat loss. Stay as motionless as possible, protect the high heat loss areas of your body, and keep your head and neck out of the water as possible as much as possible. Safety usually looks closer than it actually is, so staying with the boat is usually a better choice than swimming. Adopt a position to reduce heat loss. If alone, use the HELP (Heat Escape Lessening Posture) position or if there are others in the water with you, huddle together. If you must swim, conserve energy and minimize your movement. Swim on your back, use a Flutter-kick with your lower legs, keeping your upper arms against the sides of your chest, your thighs together, and your knees bent.

6. Be prepared at all times to signal rescuers by waving arms or a flag.

7. If someone falls overboard, get the victim out of the water in a timely manner, and as gently as possible, in a horizontal position.

Victims may deny they are ill and want to decline medical care, or want to climb into ambulances or helicopters on their own. Remember their judgment may be clouded, and yours should prevail.

The following chart provides a general idea of survival times in water of varying temperatures. Factors that may alter these estimates include clothing or protective gear, the individual's health condition, and water conditions.

Falling into cold water triggers a gasping reflex, causing the victim to inhale water. Total immersion in cold water is very painful and the disoriented victim can quickly panic. With these combined reactions, the victim may drown quickly. The best prevention for this danger is to wear a life jacket with a cold-water survival suit.

Swim Failure

After a person has been in cold water for 3-30 minutes there's a continued inability to hold one's breath, loss of coordination in the arms and legs results in a body-angle incompatible with swimming…this results in the use of excessive amounts of energy in an attempt to swim, there is reduced ability to match breathing with swimming efforts and as a result of uncoordinated swimming, it becomes more and more difficult to keep the head above water.

Cold Water Immersion

Quick response to cold water immersion is vital because the body is impacted immediately:

In the first 3-5 minutes, sudden immersion can cause immediate hyperventilation, panic, involuntary gasping for breath, or vertigo. There might also be sudden changes in blood pressure and heart rate of the individual. These are symptoms of "cold shock" can all be fatal.

The next 3-30 minutes the muscles and nerves in the arms and legs cool, causing a loss of manual dexterity and strength. "Swim failure" occurs when someone, even a strong person, lacks the coordination and strength to swim, pull them selves out of the water or prevent their head from being submerged underwater. Drowning and death are a concern when this happens.

After 30 minutes, depending on the water temperature, the victim's body type, their clothing, and their behavior in the water, long-term immersion hypothermia sets in. The body is losing heat, especially in vital organs, faster than it can produce it. Hypothermia eventually leads to loss of consciousness and death, whether or not the person is in the water or not.

If a person is lucky enough to be rescued, they are still in danger from collapse of arterial blood pressure leading to cardiac arrest in a post-immersion collapse. Also, any water inhaled by the person can damage the lungs, and problems related to the heart may develop as cold blood from arms and legs is circulated into the body's core.

Submersion accidents which lead to unconsciousness in waters colder than 70° occur with regularity. Oxygen needs are much reduced when the body is cold, therefore permanent brain damage from low oxygen states may not occur.

It is documented, that a 60 minute cold water submersion victim has been fully resuscitated. Similar to a hypothermic victim, these "victims of cold water submersion" appear cold to the touch, blue in color, with no noticeable respiration or evident circulation and their pupils are fixed and dilated.

A consequence of immersion injury is prolonged low oxygen level in the blood (hypoxemia). After initial gasping, and possible aspiration, immersion stimulates hyperventilation, followed by voluntary cessation of breathing and a variable degree and duration of laryngospasm. This leads to hypoxemia. Depending upon the degree of hypoxemia and resultant acidosis, the patient may develop cardiac arrest and central nervous system (CNS) lack of blood supply. Asphyxia leads to relaxation of the airway, which permits the lungs to fill with water in many individuals ("wet drowning"). Approximately 10-20% of individuals maintain tight laryngospasm until cardiac arrest occurs and inspiratory efforts have ceased. These victims do not aspirate any fluid ("dry drowning").

Factors relating to surviving cold water near-drowning:

1. Age of the patient - the younger the better the prognosis

2. Length of submersion - the shorter the better

3. Water temperature - the colder the better the chance of survival

4. CPR - if appropriately applied the better the survival

5. Water Quality - the cleaner the better the survival

6. Struggle - the more struggle the worse the results

7. Other injuries - burn, blast or fractures reduce the chance of survival