What is Hypothermia?
Hypothermia is a medical condition that occurs when the body loses heat faster than it can produce, causing the core temperature to fall dangerously below normal (36.9°C / 98.6F).
In moderately cold environments, the body's core temperature does not usually fall more than 1°C to 2°C below normal because of the body's ability to adapt. In extreme cold, and without adequate clothing (insulation), the body is unable to compensate for heat loss causing the body's core temperature to fall. The first sign of hypothermia is the sensation of cold, followed by tingling pain, that occurs in the extremities and exposed areas.
As heat loss continues, the pain may become numbness and eventually loss of feeling. At this point, permanent damage to tissues can occur.
As the body's temperature falls below 35°C / 95F, muscle weakness, confusion, and drowsiness are experienced. A further decrease in temperature can lead to coma (27°C / 82F), cardiac arrest (20°C / 68F), and at 17°C / 63F the brain's function ceases.
Signs & Symptoms
Hypothermia can be prevented by wearing proper clothing and footwear. Extremities such as hands, feet, ears, and nose are most susceptible to cold temperatures. Moisture reduces the insulating value of clothing, so it is important to choose the right garment for the activity. Cotton fibres retain moisture and sweat, therefore cotton socks should be avoided during physical activity. Wool and synthetic fibres are better at wicking moisture away from the skin. Stay dry and seek shelter when needed. Be active/keep moving (without breaking a sweat) unless you need to preserve energy.