Hypothermia: A Potential Killer Anytime, Anywhere

It was March in South Louisiana and the last real cold front of the year whipped the water into an angry, foamy mass of three ft. high waves. A small workboat bounced against the pilings as two workers and their supervisor loaded their gear in preparation for servicing an oil well located in a nearby bay. Struggling to stay on his feet, one of the workers told the supervisor he didn't think it was a good idea to go out in such a small boat under such rough conditions. The supervisor smiled condescendingly and dismissed the advice. Silently, the workers braced themselves as the supervisor revved the outboard and the boat pulled away from the dock. After a long, tiring day of fighting wind and waves, the men completed their work and headed back toward the dock. It was cold by Louisiana standards, in the low fifties, and the wind and creeping darkness made it seem even colder. The chill and the bucking of the vessel made everyone miserable and their thoughts - especially those of the supervisor - were focused on getting home as quickly as possible. Not a word of protest was spoken as he crashed the workboat into the oncoming waves like an offshore racer headed for the finish line. In the blink of an eye, the men's thoughts turned from home to a struggle for survival. As the boat surged over one of the waves, a sudden gust of wind caught it and flipped it over. The disoriented men clawed like cats at the slick aluminum hull trying to free themselves from the grip of the unpleasantly cold water. It soon became obvious their efforts to get on top of the overturned boat were futile; so, they hurriedly swam to a nearby wellhead and pulled themselves on the work platform surrounding it. There, they spent the next 12 hours with wind steadily whisking away the heat from their bodies as they huddled together on the lonesome, steel island. When the rescue team finally arrived, hypothermia had nearly claimed the men's lives. In fact, the rescuers initially thought the men were dead, since they were unconscious and no pulse could be felt at the wrist. It was only after one of the alarmed rescuers checked the carotid pulse point that a flicker of life was detected. Gently, the stiff bodies were lowered to the rescue vessel where their damp clothing was carefully removed and replaced with warm blankets as the boat rushed for the ambulance waiting at the dock. In the hospital, the men were slowly rewarmed as doctors closely monitored them for any signs of heart arrhythmias, such as ventricular fibrillation. The injured men gradually recovered, although two of them suffered neurological problems affecting their extremities that persisted for several months. Hypothermia is a potentially life threatening hazard for personnel who work around water, even in places like Louisiana and Florida. It is a hazard workers must take seriously all year round and in all geographic areas. Hypothermia is a condition in which the body is cooled below the optimum temperature necessary for the chemical reactions that support life to occur. The body is capable of increasing its temperature in response to slow, relatively minor changes in the ambient temperature by metabolizing food. Since water is a very efficient conductor of heat, immersion can produce a rapid decrease in temperature for which the body cannot compensate. Research has shown the body has trouble warming itself up any time water temperature is less than 70 degrees F. This is a relatively warm water temperature usually only exceeded in the late spring, summer and early fall in bodies of water located in the southern states. In many areas of the U.S. and Canada, prolonged exposure to the water can result in hypothermia at any time of the year (If you have any doubts, try swimming in Lake Huron in June.) Even if a person who has fallen overboard manages to get out of the water, they are still in danger. An individual wearing wet clothing in the open air will lose heat five times faster than when they are dry. This is why it is important to get a hypothermia victim out of wet clothing and into something dry as quickly as possible. Hypothermia progresses through several stages. In mild hypothermia, the core temperature is between 98.6 and 96 degrees F. The victim will experience shivering, pale tissues in the extremities, and difficulty performing complex motor functions. In moderate hypthermia, the victim has a core temperature between 95 and 93 degrees F. The victim will appear dazed and may exhibit irrational behavior along with violent shivering and loss of fine motor control. An individual in this condition will probably drown if they are in the water without a personal floatation device. In severe hypothermia, the victim has a core temperature between 92 and 86 degrees F. The victim will be incoherent and experience shivering waves with pauses of increasing length until shivering finally ceases, depressed vital signs, dilated pupils, and muscle rigidity. When treating hypothermia victims, it is important to reduce further heat loss. The two most critical steps in preventing further heat loss are to shelter the victim from the wind and replace wet clothing with dry clothing. For victims with mild to moderate hypothermia, insulation should be placed under them and they should be covered with a warm blanket. The victim can be rewarmed by heat packs, warm water bottles, or by body contact with another person. The best places to apply the heat sources are areas where blood vessels are close to the surface, such as the neck. Regardless of the method, rewarming should occur in a relatively slow, steady manner. For victims with severe hypothermia, it is recommended separate blankets be used to wrap each extremity and the trunk of the body. This is done to prevent the extremities - which tend to be colder than the rest of the body - from contacting the trunk and further reducing the core temperature. With severe hypothermia victims, rewarming should occur at a hospital if possible. Unless the core temperature is raised first, the cold, acidic blood in the extremities may rush to the core causing cardiac arrythmias. If a hospital is not nearby, apply heat sources only to the trunk of the body and increase the temperature very slowly. With victims in severe hypothermia, the heart is hyperexcitable . Sudden temperature changes and mechanical shocks, such as jarring or chest compressions, can induce ventricular fibrillation. Never perform CPR on a hypothermia victim until the carotid pulse has been checked for at least one minute. The heart rate may be very slow and difficult to detect. Cold water is a killer. Workers must have a healthy respect for the marine environment and do everything possible to stay out of the water. One poor decision in a cold, wet environment could cost a worker his life. Charles Simpson, CSP, is a New Orleans-based consultant, specializing in safety issues related to hazardous chemicals. He can provide assistance with training and the development of written safety programs. Contact him at Safety Consulting Associates; tel: 504-624-8060