The polar vortex that’s expected to hit the eastern U.S. starting Tuesday night is forecast to bring sub-zero temperatures, but little snow to Cranberry. Township officials encourage residents to take appropriate precautions: dress in layers of clothing including gloves and a hat; frostbite can happen quickly. Open under-sink cupboards and run water at a trickle to prevent pipes from freezing. Bring pets indoors. Don’t use your stove to heat the home. Stock up on any needed provisions before the weather gets too cold.