When skin and underlying tissues freeze after exposure to very cold temperatures, that's frostbite. Hands, feet, nose and ears are most at risk. The key to treating frostbite is to gradually warm the skin, which may feel red and painful as it thaws.
Hypothermia takes place when someone’s body temperature drops below 95°F. Severe hypothermia can divert blood away from the heart or nervous system, and in extreme cases, lead to organ failure, or even death.
But Cindy Lord, director of the Quinnipiac University Physician Assistant program, said that even mild hypothermia can have real consequences, "things like faster breathing, more rapid heart rate," she said. "People could have trouble speaking. They might become confused."
Lord uses an acronym, COLD, when offering advice to avoid hypothermia.
C is for cover. Of course you want to cover your hands, feet and head. She said that hats do help. "And you know," she said, "people always think about gloves, but actually mittens are better, because it keeps your fingers, your body parts closer together. O is for over exertion. We encourage people to avoid activities where they might sweat a lot, because you lose body fluids, and with that, you actually lose heat."
L is for layers. It's best to wear loose-fitting, lightweight outer clothing. Underneath, wool and silk are better at holding in heat than cotton. Finally, D is for dry. If you work up a sweat, get back inside as soon as possible, and change into dry clothing.
And there’s another thing: Cindy Lord recommends avoiding alcohol and certain medications that can aggravate hypothermia.