Basically, hypothermia occurs when the body temperature becomes abnormally low (generally falling under 95°F, causing the body to slow down, or even shut down in severe cases, and can make it extremely difficult for victims to move well and think clearly. While it generally occurs after prolonged exposure to very cold temperatures, hypothermia has been known to set in when it is above 40°F if the person becomes chilled from rain, is submersed in cold water, and even from sweating.
Those at the greatest peril are the homeless, people who work outdoors in extreme cold, hikers, hunters, babies left in cold bedrooms, the poor and elderly who don’t have adequate food, clothing, or heating and both drunk addicts and alcoholics, etc. The most common symptoms include shivering, drowsiness and exhaustion, confusion, inability to hold onto things, memory loss and slurred speech. Babies may also exhibit cold, bright red skin and lethargy.
If you see someone exhibiting these signs, get them out of any wet clothing immediately and bring them into a heated room or shelter. Keep them dry and begin warming them up, especially around the chest, head, neck and groin using blankets (electric if possible), or use your own body through skin-to-skin contact. Warm beverages will also help. But do not give them alcohol, which will cause blood vessels to rise up closer to the skin, bringing the temperature down even more. Another thing, do not try to pour liquid down someone’s throat if they are unconscious. Finally, get them to a doctor or emergency room as soon as possible.
Frostbite, on the other hand, occurs when a body part actually freezes. While mild frostbite doesn't leave lasting damage, severe frostbite does cause permanent damage and may even require amputation of the frozen part. Signs include white or grayish-yellow skin area, numbness and skin that feels unusually hard or waxy.
The first thing to do is get the person into a warm room. However, if their feet or toes are frostbitten, do not let them attempt to walk on them unless there is not other choice. Doing so will only cause more damage. Next, immerse the frostbitten area in warm (not hot) water. Placing fingers under an armpit can also help.
Contrary to popular belief, never rub snow or massage frostbitten areas. This too will actually cause more harm. In addition, health experts warn people “not to use stoves, fireplaces, radiators, heating pads or heat lamps for warming, since parts that are numb can easily burn.”
Parts more susceptible to frostbite are noses, ears, and chins, cheeks, fingers and toes. The risk of frostbite is increased in people with reduced blood circulation such as diabetics and smokers, and individuals not dressed properly for extremely cold temperatures.