The seasonal cold fronts now arriving in the Keys may bring us many benefits, but they also present a few hazards for the boater and diver. While our hotels fill with migrating tourists, our waters are filled with migrating bait fish, mackerel, kingfish and cobia. This indeed is an exciting time to be on or in the water.
The north winds and heavy seas that accompany the cold fronts require the small boater and divers to be extra cautious. Even in this subtropical clime, our local waters during the winter become rough and cold enough to make hypothermia a real danger to people in the water for long periods of time.
Hypothermia results from prolonged exposure of the body to temperatures colder than our body that result in the lowering of overall body temperature and eventual loss of mental and physical capacity. It starts when you begin to shiver and your feet and hands start to become numb.
It may seem a bit odd to many of our new residents and northern visitors, especially given the relatively mild winters we have, but it is important to remember that the waters in the Florida Keys during the winter can be threatening or even deadly.
Lately, our water temperatures have been in the lower 70-degree range. Although it may not seem cold at first, this is 28 degrees below our normal body temperature.
Divers who intend to make multiple dives should wear a suitable wet suit. Snorkelers should not remain in the water once they start to shiver. And boaters should consider carrying a wetsuit as a personal safety device in case their boat sinks leaving them stranded in the cold waters. Swimming in cold water causes increased heat loss and chills your body faster by forcing blood into the large muscles of the upper body where it is cooled as it flows close to the skin. Upon returning to the heart and deep body areas, this cooled blood lowers the bodys core temperature.
If your boat should capsize, simply stay with it. A lifejacket or personal floatation device keeps you afloat and helps to conserve heat. In addition to the PFD and staying with your boat or other floating debris, if you do not have a wetsuit, you should attempt to assume a fetal-like position with the head out of the water, holding the inner side of your arms tight against the sides of your chest and raising the thighs to close off the groin area. The reason for holding this position is because you lose the most heat from your head, armpits, and groin areas. To help someone who has suffered from hypothermia, you must handle the victim gently.
First, stop the heat loss by insulating the body and head from cold air or a cold deck and very gradually rewarm the body and extremities. Also wrap the legs and arms, but under no circumstances should you try to actively rewarm the extremities because it may cause additional injury.
Only the body core (head, neck, trunk and groin) should be rewarmed. Warm mild dry heat is best. Do not put the victim in warm water because the recovery process must be gradual.
You can use heating pads, chemical heat packs, and even your own body heat to warm a victim of hypothermia. Any symptom beyond simple shivering is a warning that medical attention is needed as soon as possible. Also avoid providing coffee, tea cocoa or alcoholic beverages. Non-alcoholic warm fluids, particularly water and fruit juices, are best.
Ideally, you want to avoid putting yourself in such an emergency situation. Make an effort to develop cautious, safe boating practices.
Doug Gregory is marine agent for the Monroe County Cooperative Extension Service.