Clap hands and move arms and legs occasionally. Try not to stay in one position for too long. If more than one person is in the car, take turns sleeping. For warmth, huddle together. Use newspapers, maps, and even the removable car mats for added insulation.
Cold weather puts an added strain on the heart.
Unaccustomed exercise such as shoveling snow or pushing a car can bring on a heart attack or make other medical conditions worse. Be aware of symptoms of dehydration. Contact your local Emergency Management Office or National Weather Service Office for more information on winter driving.