Mayo Clinic defines Hypothermia as a "medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. When your body temperature drops, your heart, nervous system and other organs can't work normally. Left untreated, hypothermia can eventually lead to complete failure of your heart and respiratory system and to death."
The U.S. National Institutes of Health (NIH) provides the following information on how to stay safe during the cold season and prevent hypothermia.
§ Try to stay away from cold places. Changes in your body that come with aging can make it harder for you to be aware of getting cold.
§ You may not always be able to warm yourself. Pay attention to how cold it is where you are.
§ Check the weather forecasts for windy and cold weather. Try to stay inside or in a warm place on cold and windy days. If you have to go out, wear warm clothes including a hat and gloves. A waterproof coat or jacket can help you stay warm if it's cold and snowy.
§ Wear several layers of loose clothing when it's cold. The layers will trap warm air between them. Don't wear tight clothing because it can keep your blood from flowing freely. This can lead to loss of body heat.
§ Ask your doctor how the medicines you are taking affect body heat. Some medicines used by older people can increase the risk of accidental hypothermia. These include drugs used to treat anxiety, depression, or nausea. Some over-the-counter cold remedies can also cause problems.
§ When the temperature has dropped, drink alcohol moderately, if at all. Alcoholic drinks can make you lose body heat.
§ Make sure you eat enough food to keep up your weight. If you don't eat well, you might have less fat under your skin. Body fat helps you to stay warm.
From NIH.gov