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.
Stages of 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 mild 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.
