Successful egress from an inverted seaplane into the water is only the beginning of the survival process. The pilot may be the only person who understands the effects of cold water, even water only a few degrees cooler than normal body temperature, on the human body. Seaplane accidents that occur even on small bodies of water may mean a wait for rescue, especially if the location is remote. Furthermore, even if the evacuees make it to shore fairly quickly after submersion, they may still have to deal with the effects of cold temperatures even if it is just evaporative effect. Especially for seaplanes operating into remote areas, operators should consider stocking the seaplane with survival gear appropriate for the operation. The survival kit should be assembled in one container that is leakproof, easily accessible, and, preferably, floatable. Some Alaskan and Canadian operators attach a rope and a float to the survival kit to allow for easier recovery once everyone has exited the aircraft. This has proved quite successful in emergency situations in some of North America's harshest terrain.
a. Hypothermia. Cold water (less than 70 degree F) lowers body temperature rapidly, creating a condition called hypothermia. Hypothermia means that the body's inner core temperature has begun to descend significantly below the body's norm of 98.6 degree F. A drop of only three or four degrees in body temperature could overload the heart, impair circulation, and lead to irreversible brain damage. (Hypothermic persons generally lose consciousness and drown before these effects can occur.)
(1) Even though a person may be wearing a life jacket-type life preserver, the body cools down 25 times faster in cold water than in cold air. Water temperature, body size, amount of body fat, and movement in the water are all factors that play a part in how quickly a person becomes hypothermic and, therefore, in that person's survival. Generally, small people cool down faster than larger people; children cool down faster than adults.
(2) Flotation gear can still help a person stay alive longer in cold water because they allow the person to float without expenditure of energy; i.e., the person's movement in the water can be used exclusively for moving toward shore rather than trying to stay afloat. Flotation gear also protects the upper torso somewhat from the effects of cold water. For example, a snug-fitting life vest would be more effective in keeping the upper torso warm than a loose fitting one or a seat cushion used as flotation gear.
b. Effects of Hypothermia. The exact nature of the hypothermic process
is not yet fully understood. The following table provides some indication
of the onset of unconsciousness and the expected time of survival in water
of specific temperatures.
*Information from Underwriters Laboratory, Inc.
c. Handling Victims of Hypothermia. A hypothermic person requires special attention, and rescue personnel (and this could be the operators personnel who have no medical training) should be aware of the following guidelines on how to handle victims of hypothermia.
(1) Lack of movement does not mean dead. Rescue personnel should make no assumptions based only on the victim's appearance, touch, or absence of a discernible pulse or breathing. In deep hypothermia it is not always possible to make an on-site determination whether a person is still alive. Some medical experts believe that deep hypothermia places the body in a state similar to hibernation, where brain and other organ functions become depressed, therefore requiring less oxygen from a reduced bloodflow. Some victims have been revived, but the extent of injury or damage from the hypothermia has varied.
(2) Rescuers should NOT warm the victim externally, such as by immersion in warm water or by applying heat directly to the body. Rescuers should cover exposed skin with a blanket and provide shelter but should avoid abrupt temperature changes in the victim's immediate environment. The rescuers should arrange for transport to a medical facility as soon as possible.
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