First of all, if you feel you are suffering from frostbite, you should seek professional medical attention while trying to keep pressure off of extremities (fingers and toes) that have been frozen. You should never vigorously rub the afflicted area as this could cause severe tissue damage or even break off pieces of tissue. If you are unable to see a doctor immediately, a warm bath (have the water between 100 and 110°F [38 to 43°C]) is a much better choice than sitting in front of a fireplace.