New Zealand climber Mark Inglis shows his badly frostbitten fingers as he arrives at Auckland International airport after returning from Kathmandu.

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Frostbite and Hypothermia

The two main cold-weather illnesses are frostbite and hypothermia. Frostbite means that yo­ur skin has fallen below the freezing point, and ice crystals are forming within your skin cells, killing them. If you're able to warm your skin, it will form a blister, change from blue to black in color and harden into a shell. This shell will eventually fall off to expose new skin underneath if the damage isn't too severe. This is the very painful "superficial" frostbite. Severe frostbite penetrates all the way to the muscle and bone and is characterized by tingling of extremities and changes in your skin's color and texture. The stages of frostbite are:

  • Red skin - initial stage
  • White skin - middle stage
  • Hard skin - getting severe
  • Blisters - severe
  • Blackened skin - advanced stage

Severe frostbite usually causes tissue damage, and can even lead to amputation of fingers, toes, hands and feet. It's vital when afflicted with frostbite to warm your skin gradually. Cover your ears and put your fingers under your arms. Don't ever rub the damaged skin or submerge it in hot water -- you'll cause even more damage. Water between 100 and 106 degrees Fahrenheit is ideal to use as a warming agent. If you can, get into a warmer area immediately, even if it's just a tent or shelter. Remove any tight clothing that may restrict blood flow. You can put gauze or cloth between your fingers and toes to soak up moisture and prevent them from sticking together. It also helps to slightly elevate the affected area to reduce swelling.

Hypothermia is when your body loses more heat than it produces and your core body temperature drops. Some of the symptoms of hypothermia are:

  • Slurred speech
  • Stiff joints
  • Loss of coordination
  • Slow pulse
  • Uncontrollable shivering
  • Loss of bladder control
  • Puffy face
  • Mental confusion

Many times, getting wet in addition to the cold leads to hypothermia, and the result can be as severe as coma or death. To combat hypothermia, get yourself into a warmer environment as soon as possible. Cover with any items you can find -- blankets, sleeping bag, pillows or even newspaper. Most heat is lost through your head, so cover yours immediately if it's not already. If you have on wet clothing, take it off and replace it with some dry duds. If you have no dry clothing, it's better to strip naked than to wear something wet. You should always handle hypothermia victims carefully, as it's easy for them to go into cardiac arrest. Keep them horizontal and calm -- reassure them that they're going to be fine. If you're with someone, get into a sleeping bag together or simply hug each other tight to create warmth. If you're not trapped in the wilderness, seek professional medical attention as soon as possible.

In the next section, we'll look at how your shelter plays a part in cold weather survival.