Hypothermia

Hypothermia is a condition where the body becomes dangerously cold. It can be caused by brief exposure to extreme cold, prolonged exposure to mild cold, from being cold and wet, or under cold water for too long. In cold weather, your body may lose heat faster than you can produce it. Hypothermia occurs when a person’s deep-core body temperature drops below 35 degrees Celsius (95 degrees Fahrenheit). The onset can be subtle and creep up on the person. Hypothermia can occur in temperatures below or above freezing.

Symptoms of mild hypothermia include shivering, slurred speech, memory lapses and fumbling hands. Victims frequently stumble and stagger, but are usually conscious and can talk. While many people suffer cold hands and feet, victims of mild hypothermia experience cold abdomens and backs.

With severe hypothermia, shivering stops and muscles become stiff and rigid. The victim’s skin is ice cold and looks blue, and pulse and breathing slow down. Pupils dilate. You might even think the victim is dead.

For both types of hypothermia, get the victim out of the cold and near a stove, fire or other heat source. Add insulation beneath and around the victim. Cover the victim’s head, since 50% of the body’s heat loss is through the head. Take off and replace any wet clothing. Handle the victim gently, and maintain the victim in a horizontal (flat) position.

With severe hypothermia, you will need to check the victim’s airway, breathing and circulation. Take 30-40 seconds to check the pulse. Provide as much heat as possible.

StageCore
Temperature
Signs & Symptoms
Mild Hypothermia37.2-36.1ºC
(99 – 97ºF)
Normal, shivering may begin.
36.1-35ºC
(97 – 95ºF)
Cold sensation, goose bumps, unable to perform complex tasks with hands, shivering can be mild to severe, hands numb.
Moderate Hypothermia35-33.9ºC
(95 – 93ºF)
Shivering, intense, muscles de coordination becomes apparent, movements slow and labored, stumbling pace, mild confusion, may appear alert. Use sobriety test, if unable to walk a 30 foot straight line, the person is hypothermic.
33.9-32.2ºC
(93 – 90ºF)
Violent shivering persists, difficulty speaking, sluggish thinking, amnesia starts to appear, gross muscle movements sluggish, unable to use hands, stumbles frequently, difficulty speaking, signs of depression, withdrawn.
Severe Hypothermia32.2-30ºC
(90 – 86ºF)
Shivering stops, exposed skin blue of puffy, muscle coordination very poor, inability to walk, confusion, incoherent/irrational behavior, but may be able to maintain posture and appearance of awareness
30-27.8ºC
(86 – 82ºF)
Muscle rigidity, semiconscious, stupor, loss of awareness of others, pulse and respiration rate decrease, possible heart fibrillation.
27.8-25.6ºC
(82 – 78ºF)
Unconscious, a heart beat and respiration erratic, a pulse may not be palpable.
25.6-23.9ºC
(78 – 75ºF)
Pulmonary edema, cardiac and respiratory failure, death. Death may occur before this temperature is reached.