The Effect of Extreme Cold: hypothermia

The Effect of Extreme Cold: hypothermia

Exposure to excessive cold is as dangerous as exposure to excessive heat, with frostbite and hypothermia (a drop in body temperature) the most serious consequences. To a lesser degree, fatigue, numbness, chills, muscular cramps, tingling and aching are also symptoms of overexposure to the cold. They are nevertheless easy to avoid.


Hypothermia is a state during which the body’s temperature drops because the body loses heat faster than it produces it. There are two stages of hypothermia - mild and severe.

Mild hypothermia

Mild hypothermia occurs when the body temperature drops below 37° Celsius. Breathing and pulse accelerate; shivering increases, the hands and feet are white and cold. The first signs of someone with mild hypothermia are fatigue, shivering, irritability, and inappropriate language or behaviour. These victims must be encouraged to move around in order to generate muscle warmth. They must stay out of the wind and rain, and all wet clothing should be replaced with dry articles. Give them hot drinks and and keep them warm, insisting particularly on the thighs, the head, neck and thorax.

Severe hypothermia

Severe hypothermia occurs when the body temperature falls below 33° Celsius. In this case, the situation is much more serious. The victim no longer feels any chills or shivering, the muscles begin to stiffen and the person’s lips and extremities turn blue. Pulse and breathing gradually slow down; feelings of confusion and indifference begin to manifest, followed by drowsiness, then loss of consciousness and eventually a coma. At less than 30° Celsius, the vital signs can no longer be detected and the victim appears dead: the pupils are fixed and dilated, the pulse cannot be detected, breathing is very weak and heart failure can cause death to occur at any moment. All victims of severe hypothermia must be hospitalized immediately. While waiting for emergency assistance, take care of the victim: cover him/her with thick blankets and carefully carry the person to a place protected from the cold. Warming the victim must happen gradually (dry clothes, additional sources of heat in the room…); however, in this particular case, do not rub the body’s extremities, expose the victim to a direct source of heat, or administer hot drinks that will cause the body’s internal temperature to rise too quickly and could be very dangerous for someone who appears to have lost consciousness. As always, it is absolutely critical to call the Fire Department or the Ambulance Services immediately.


Frostbite affects the body’s extremities (feet and hands), ears, nose and cheeks. Frostbite can be extremely serious and lead to amputation of those affected body parts or cause serious after-effects. A gradual loss of feeling, numbness or dullness, a pale colour or a turning blue of the effected areas are all warning signs. In this case, slowly and continually heat the affected areas, as well as the rest of the body, but avoid significant differences in temperature. For example, do not put a frozen extremity in very hot water or expose it to a flame. And never rub, tap or hit the frostbitten areas.