Hypothermia And Cold Shock — The Risks Of Off-Season Boating
By Tom Nunes
Warm (hot) weather boaters have left the water and are dreaming of spring. Crowds are gone from Arizona lakes during colder months, leaving only wind to ripple the surface.
A few die-hard fishermen still work their favorite spots, enjoying peace and quiet. Bundled up against the cold, waterfowl hunters also take advantage of now nearly empty waterways. The crisp, clear days represent the best of times for many boaters.
Enjoying these good times does not come without the risk of paying a heavy price. The water is cold, with water temperatures often under 60º F, making a fall into the water the potential for a fatal accident.
Never Go Out Alone
Sharply reduced boating traffic adds to danger by making an immediate or prompt rescue highly unlikely. Off-season boaters need to be doubly careful and avoid solo trips.
The main objective is to avoid entering the water because immersion in cold water rapidly incapacitates and may quickly kill boaters who are not wearing protective clothing. Surfers, sailboarders, kayakers, and other folks in similar sports wear wetsuits or dry suits to protect themselves from the cold water.
Smart off-season boaters, including sailors, fishermen, hunters, and others take similar precautions to improve their safety while on the water — including never going out alone.
To properly prepare, you have to first understand what happens to your body in cold water. Water removes heat from a body 25 times faster than cold air, with most body heat lost through the head. Swimming, thrashing about, and other physical activity increases heat loss through limbs and extremities.
If you become a person in the water (PIW) you will sharply reduce your survival time though physical activity. Strong swimmers wearing a life jacket have died before they covered 100 yards in cold water.
Cold Shock Can Lead To Cardiac Arrest
Cold shock is the body’s reaction to the shock of cold water. During cold weather everyone should wear a life jacket. (You should always wear your lifejacket, but you really need to wear one when the water is cold!)
Cold shock can trigger an involuntary gasping reflex that will cause you to inhale water through your mouth. Without a life jacket, a person can drown without ever coming back to the surface.
Wearing your life jacket will increase the likelihood of survival if you should accidentally fall into the cold winter water. Cold shock may also result in cardiac arrest. When the head and chest are exposed to cold water, the result is often a very sudden increase in heart rate and blood pressure.
Cold water immersion can also result in immediate loss of consciousness, but, depending on the type of life jacket worn, an unconscious victim can survive without drowning.
Hypothermia May Cause Loss Of Consciousness
Hypothermia, in layman’s terms, is decreased body temperature. This condition develops more slowly than the effects of cold shock, and you may not be immediately aware of the symptoms.
Remember that symptoms of hypothermia include shivering as the body loses heat and body temperature drops. Uncontrolled rapid breathing follows the initial gasping response and may cause a loss of consciousness.
Muscle rigidity and loss of voluntary motor function results in physical helplessness. A hypothermia victim starts to shiver as core body temperature falls from 97ºF down to about 90ºF.
A person at risk of hypothermia must try to control his breathing rate to avoid hyperventilation, leading to unconsciousness following the immediate involuntary gasping response to the initial immersion into cold water. Uncontrolled or rapid breathing will speed up the chilling process.
If the victim doesn’t drown first, hypothermia will finish him off when the body temperature falls to or near 80ºF. Survival figures show that an adult dressed in average clothing may remain conscious for one hour in water at 40ºF, and perhaps as long as two to three hours in 50ºF water.
Remember, any movement in water accelerates body heat loss. Unnecessary movement can reduce survival time to minutes.
Stay Together; Stay Still
Avoid venturing out onto cold, wintry waters alone because a buddy can save your life. If you find yourself in cold water, try to get back on your boat immediately.
If the boat capsizes, do not leave the boat because the overturned boat is easier to spot than a single person in the water. If you are not wearing thermal protection and you can’t get out of the water, keep as still as possible.
Fold your arms against your chest, cross your legs to reduce the amount of cooling surface. Rely on the buoyancy of your life jacket and float quietly until help arrives.
If two or more people are in the water, huddle close together. Put your arms around each other to slow down heat loss.
Planning Is Essential
Planning for cold weather off-season boating is essential. Wear clothing that will protect you in the event of cold-water immersion. Always wear your life jacket.
On land, conventional wisdom advises that you wear layers of warm clothes. On the water, this will not help you.
Survival suits, like the Stearns and Mustang types, are available from local boating equipment retailers or though catalogues. You can also wear cold-water survival suits under your regular clothes. These suits are worn by windsurfers and river paddlers and are similar to a diver’s dry suit.
As you plan your trip, you should pack dry clothing in a waterproof bag. Make sure your boat has adequate bailing equipment.
You may want to make provisions to facilitate re-entry into your boat by having a boarding ladder or even a line over the side. Your life jacket should have a sound -producing device such as a whistle or horn and a reflective device attached to it.
Before you leave home, check the weather forecast. A cold rain can soak you and bring on hypothermia almost as fast as a dunking. Prepare a float plan and leave it with someone, or at least notify someone where you are going and when you expect to be back.
When you return, let others know you’re back. Never go out alone. Using the buddy system is a proven lifesaver.
While you are out, observe boats around you, their location and proximity to your boat. On cold water, you have to depend on each other for quick rescue in case of an accident. You know, you watch them, and they watch you, and you help each other out.
If you are going out into cold weather, on the water or on land, you may run into someone who is experiencing hypothermia. You might be able to save that person’s life by knowing the right way of providing first aid.
Hypothermia First Aid
In Summary, Ensure Your Return
Cold weather boating has its rewards for the prudent mariner. Following a few simple rules will help keep your safe, or at least increase your chances of returning home.
Nearly every one of those missing mariners was not wearing a flotation device. File a float plan. Never go out alone. Check the weather before leaving home. While on the boat, keep an eye on the weather and know when to quit and head for home.
Even in cold weather, leaving the dock is optional, but returning is mandatory.