Several fans of the Kansas City Chiefs who attended a playoff game on a bitterly cold January day in Missouri suffered frostbite that required amputations, according to the hospital that treated them.Twelve people — including some football fans who were at Arrowhead Stadium on Jan. 13 — had to undergo amputations involving mostly fingers and toes, the hospital, Research Medical Center in Kansas City, said in a statement on Saturday.The center said it treated dozens of patients who experienced frostbite during an 11-day cold snap. Not all of the patients who had amputations attended the…