Frostbite and hypothermia are cold-related emergencies that may quickly become life or limb threatening. Preventing cold-related  emergencies includes not starting an activity in, on, or around cold water unless you know you can get help quickly in an emergency.

How to Prevent Cold Related Illness

Be aware of the wind chill.
Dressappropriately and avoid staying in the cold too long.
Wear a hat and gloves when appropriate with layers of clothing.
Drink plenty of warm fluids or warm water but avoid caffeine and alcohol.
Stay active to
maintain body heat.
Take frequent breaks from the cold.
Avoid unnecessary exposure of any part of the body to the cold.
Get out of the cold immediately if the signals of hypothermia or frostbite appear.

Frostbite

Frostbite is the freezing of a specific body part such as fingers, toes, the nose or earlobes.
Signals of frostbite include—lack of feeling in the affected area;skin that appears waxy, is cold to the touch, or is discolored (flushed, white or gray, yellow or blue).

What to do for frostbite:
1. Move the person to a warm place.
2. Handle the area gently; never rub the affected area.
3. Warm gently by soaking the affected area in warm water (100–105 degrees F) until it appears red and
feels warm.
4. Loosely bandage the area with dry, sterile dressings.
5. If the person’s fingers or toes are frostbitten, place dry, sterile gauze between them to keep them
separated.
6. Avoid breaking any blisters.
7. Do not allow the affected area to refreeze.
8. Seek professional medical care as soon as possible.

Hypothermia

Hypothermia is another cold-related emergencies. Hypothermia may quickly become life threatening. Hypothermia is caused by the cooling of the body caused by the failure of the body’s warming system. The goals of first aid are to restore normal body temperature and to care for any conditions while waiting for EMS personnel.

Signals of hypothermia include—shivering, numbness, glassy stare;apathy, weakness, impaired judgment;loss of consciousness.

What to do for hypothermia:
1. CALL 9-1-1 or the local emergency number.
2. Gently move the person to a warm place.
3. Monitor breathing and circulation.
4. Give rescue breathing and CPR if needed.
5. Remove any wet clothing and dry the person.
6. Warm the person slowly by wrapping in blankets or by putting dry clothing on the person. Hot water bottles and chemical hot packs may be used when first wrapped in a towel or blanket before applying. Do not warm the person too quickly, such as by immersing him or her in warm water. Rapid warming may cause dangerous heart arrhythmias. Warm the core first (trunk, abdomen), not the extremities (hands, feet). This is important to mention because most people will try to warm hands and feet first and that can
cause shock

Source:  http://www.redcross.org