Clothing

Layers Polypropylene/Capilene - next to skin, wicking layer
Synthetics/ wool/pile - insulation layer
Windproof shell - ie Gore-tex 2. Mittens - better than gloves
Hat - over 50% heat loss through head

Hypothermia Symptoms

98.6 Normal body temperature.
95.0 Paleness, drowsiness, listlessness, shivering. Then mental confusion, armpits and abdomen become cold, blue lips, goose bumps.
93.2 Loss of memory, movements slow and hard, irrational behavior hands can no longer hold things.
91.4 Shaking stops, unconsciousness, shallow breathing, 50% chance of survival.
89.6 Slow weakened pulse. Heart may stop. 30% chance of survival.
68-77 Heart stops.

Remove wet clothing and replace with dry as soon as possible. Feed the victim warm drinks, tea, coffee or hot soup if the victim is conscious and able to drink. May need to help victim warm up with additional heat source such as heat packs, hot water bottles or even placing a warm dry body in contact with the victim in a sleeping bag.

Frostbite

Cold, stinging, then numbness in extremities. Discoloration of flesh First white, then gray, then yellowish-gray, then blueish-purple, indicates increasing severity of frostbite.
Remove wet clothing, cover exposed skin. Try to warm injured area and keep from refreezing. Do not rub injured area with snow. Warm water at 104 degrees if possible.

Stranded in Vehicle

Don't panic - do not keep pushing on if visibility is very poor. Stay with the vehicle, better shelter and easier to find. Run motor to keep warm. Keep window cracked for air. Keep tailpipe clear to avoid carbon monoxide poisoning. Eat and drink fluids to maintain the ability to generate body heat. Drink even if you do not feel thirsty.
Exercise - move your arms and legs to help stay warm.