Prevention and Rescue

The best case scenario for Cold Water Immersion is to "reduce or prevent the risk". If you're boating in cold water, it's as simple as making sure not to overload your boat, avoiding situations where you may fall overboard and, of course, making sure that everyone is wearing a Coast Guard approved lifejacket to protect in the case of an unforeseeable emergency.

Without thermal protection you can lose body heat 25 times faster in water than in air with similar temperatures and that can be increased by a factor of up to 10 with movement like swimming or moving water.

The best choice in flotation equipment for Cold Water Immersion is a type that will offer the maximum thermal protection such as a floater jacket and pants or a one-piece survival suit. If you do find yourself in cold water, in addition to having proper flotation, there are some things you can do to delay the onset of Hypothermia. Drawing your legs up close to your chest and wrapping your arms around them in a tuck position will help conserve body heat. If you're in a group, huddling together as close as possible will also help conserve body heat.

HYPOTHERMIA DEMYSTIFIED

Hypothermia can be divided into Mild, Moderate and Severe stages. These stages are defined by the "State of Alaska Cold Injuries Guidelines for Wilderness Emergency Care". The following chart lists the signs and symptoms used in the classification of these three stages.

Classifications of Hypothermia	Core BodyTemperature	Patient's ability to rewarm without external heat source	Clinical presentation of Hypothermic Patient
Normal	Above 95ºF 35ºC	N/A	Cold sensation shivering
Mild	95-90ºF 35-32ºC	Good	Physical impairment • Fine motor • Gross motor	Mental impariment • Complex • Simple
Moderate	90-82ºF 32-28ºC	Limited	Below 90ºF (32ºC) shivering stops Below 86ºF (30ºC) consciousness is lost
Severe	Below 82ºF 28ºC	Unable	Rigidity Vital signs reduced or absent Severe risk of mechanically stimulated ventricular fibrillation (VF) (rough handling)
Severe	Below 77ºF 25ºC	Unable	Spontaneous ventricular fibrillation (VF) Cardiac arrest

TREATMENT FOR MILD HYPOTHERMIA

If there is no way to get to a medical facility within 30 minutes, a mildly hypothermic person should be rewarmed as follows. Shivering is a very effective process especially when well insulated. Shivering should be fueled by calorie replacement with fluids containing sugars. The sugar content is actually more important than the heat in warm liquids. Make sure that the person is capable of ingesting liquids without aspirating. Alcohol and tobacco use should not be permitted because they constrict blood flow.

External heat can be applied to high heat transfer areas such as the underarms and sides of the chest. Active heating of the skin is beneficial as it increases comfort, preserves energy stores and reduces cardiovascular stress

Light exercise such as walking produces heat but should only be attempted after a mildly hypothermic person is dry, has had calorie replacement and has been stable for at least 30 minutes. A warm shower or bath may be tolerated by an individual that is alert and mobile. However, this could be fatal to a moderate to severely hypothermic person and should be avoided in this case.

TREATMENT FOR MODERATE TO SEVERE HYPOTHERMIA

This is a serious medical emergency requiring proper handling and treatment and in severe cases, immediate transport to a medical facility. There are some specific things you can do to help stabilize the individual prior to the arrival of paramedics.

Great care must be taken in handling a moderate or severely hypothermic person. Extraction from the water must be as gentle as possible to avoid precipitating ventricular fibrillation. Arms, hands, feet and legs should not be rubbed or manipulated. The person should be placed n a horizontal position and wet clothing should be gently removed and the body insulated as best as possible using dry blankets, clothing or other protective materials. If shelter is available, keep the person protected from the elements and insulated from the cold ground or snow using sleeping bags, clothing, back packs or even evergreen boughs.

If vital signs are present, the person should be rewarmed as previously described but not allowed to sit or stand until rewarmed. Under no circumstances should the person be placed in a warm shower or bath, no oral fluids or food should be given and no attempts shoud be made to rewarm with exercise, including walking.

In any hypothermic individual, core body temperature continues to decrease after rescue. It is called 'afterdrop' and may last many hours in a moderate to severely hypothermic person when no shivering is present and metabolic heat production may be only 50 percent of normal. Even gradual warming of the heart will help avoid cardiac arrest and ventricular fibrillation.

Normal

Mild

Moderate

Severe