Ice Cold Water Presents Hypothermia Risk for Mariners

Each year, hypothermia claims the lives of 800 recreational boaters, commercial fisherman and merchant mariners in the United States, reports Hypothermia.org. It’s essential for captains and crewmembers to exercise precaution and follow basic safety protocols when travelling through cold waters to preempt hypothermia-related injuries and fatalities.

Hypothermia Basics

Hypothermia occurs when body temperature drops below 95 degrees; in severe cases, core temperature can drop even lower. When the body is exposed to cold for too long, it loses heat, and the body essentially continues to slow down to preserve heat. When the heart rate and brain function slows past a certain point, death occurs.

Far too many mariners are injured or killed each year by hypothermia. Northern waters where the water temperature drops to severely low levels can be dangerous if mariners don’t take proper safety precautions. In early April, for instance, a rower in Connecticut almost lost his life to hypothermia after he capsized. He was rescued by a good Samaritan, according to a Coast Guard news release, but many are not that fortunate.

The time it takes for hypothermia to set in varies widely because of numerous factors, including age, clothing, duration of exposure, and blood alcohol content. According to Minnesota Sea Grant, the expected time before a person becomes unconscious in cold water is related to the water temperature (temperatures are in Fahrenheit):

• 32.5 degrees: a person will become unconscious in less than 15 minutes;
• 32.5–40 degrees: 15 to 30 minutes;
• 40–50 degrees: 30 to 60 minutes;
• 50–60 degrees: 60 to 120 minutes;
• 60–70 degrees: two to seven hours;
• 70–80 degrees: three to 12 hours;
• 80 degrees and above: a person is not in danger of hypothermia at temperatures greater than 80 degrees.

Preventing Hypothermia

Many hypothermia cases occur in spring when mariners, boaters, or swimmers mistakenly think that because the air temperature is getting warm, that the water temperature is safe enough for swimming. Mariners who stand on deck without proper clothing in cold temperatures are also very susceptible to hypothermia.

You can lower your risk of hypothermia by:

• wearing layered clothing;
• avoiding cotton clothing, notes Minnesota Sea Grant, which is a poor insulator;
• wearing at least three layers in cold weather: Minnesota Sea Grant recommends wicking fabrics next to your skin, an insulating middle layer of fleece or wool, and a wind-proof, watertight outer layer; and
• wear a personal floatation device.

And don’t forget to use good, old-fashioned commonsense. Stay out of cold water, use good safety practices on deck, allow crewmembers to take regular breaks to warm themselves, and have a plan in place for rescue should a man go overboard.

What to Do When a Crewmember Develops Hypothermia

If a crewmember starts developing signs of hypothermia (tense muscles, low body temperature, confusion, shivering, slow pulse, shock), acceptable first aid practices include:

• removing wet clothing and taking the crewmember to a warm area;
• attempting to warm the crewmember by covering him or her with blankets and apply warm compresses;
• letting him or her ingest warm fluids if possible;and
• getting medical attention as soon as possible.

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