American football players and fans alike braved bone-chilling conditions in Green Bay Sunday during one of the coldest games in National Football League ( NFL ) history . The temperature at the Green Bay Packers ' Lambeau Field in Wisconsin was measured at four degrees Fahrenheit , with wind chill causing the mercury to dip as low as minus 14 during the visit of the San Francisco 49ers . An arctic front pushing through the Midwest , which has become known as a `` polar vortex , '' was the reason for the frigid conditions , with players donning long sleeves and balaclavas beneath their helmets in a bid to keep warm during the seventh coldest game the league has ever seen . One player who persisted with short sleeves was 49ers quarterback Colin Kaepernick , who masterminded his team 's 23-20 victory . Jim Harbaugh , coach of the San Francisco 49ers , was so concerned by the cold that he had asked Kaepernick , a Wisconsin native and childhood Packers fan , three times to wear more weather appropriate gear . `` I 'm a little hardheaded at times , '' Kaepernick , who also played without gloves , told reporters . `` I played in cold-weather games before . I feel it 's more mental than anything . '' Lambeau Field is something of an ice fortress when it comes to the NFL 's chilliest contests . The Packers ' 1967 meeting with the Dallas Cowboys , dubbed the `` Ice Bowl '' was played despite the temperature dropping as low as minus 14 -- with the wind making it feel like minus 48 -- securing its title as the coldest game in NFL history .
The San Francisco 49ers beat the Green Bay Packers in freezing conditions . Temperatures at Lambeau Field in Green Bay measured four degrees Fahrenheit . Wind chill made conditions feel like minus 14 . A man walks through a snow storm on Market Street during rush hour in downtown Los Angeles, California December 22, 2014.