The 1967 season at Lambeau Field brought the beginning of a more forgiving cold-weather experience for players, when coach Vince Lombardi had electric heating cables installed under the playing surface. The Frozen Tundra, as the field was popularly known, now had a 1700-kilowatt system that could conceivably melt accumulated ice. However, the system was faulty. During a 1997 game against the San Francisco 49ers, the turf thawed, but the ground on the sidelines remained frozen, making it impossible for the water in the center of the field to drain. The 49ers lost, and the entire grass surface and draining system had to be replaced the following week (and later replaced by a natural-gas heat system). An earlier and more famous incident occurred during the 1967 "Ice Bowl," the NFL championship game in which the Packers faced the Dallas Cowboys on New Year's Eve and the official game-time temperatures dipped to -15°F. The heating system had apparently failed. Some rumors emerged that the heating was intentionally turned off by the Packers organization to give the home team an advantage. The Packers did win the Ice Bowl, but the team maintains that the heating system broke down. In 2007, the system was replaced yet again.