"It is not that cold, it is all mental," 49ers quarterback Colin Kaepernick said. "Just look at Bow [All-Pro linebacker NaVorro Bowman] with no sleeves."
The meat-locker conditions put a chill on outdoor tailgating and had fans heading into Lambeau early to warm up with free coffee and hot chocolate.
It was 5 degrees by kickoff at mid-afternoon, though a northwest wind made it feel like minus-10. Winds increased through the evening.
"I won't lie to you. It got pretty cold," linebacker Patrick Willis said. "But as I said earlier in the week, there's no better way to warm up than to get this 'W.' "
The bitter cold apparently meant little to some of the players like Bowman. Each member of the starting offensive line of the Packers went sleeveless under green jerseys. The sleeveless look also fit for Kaepernick.
"It was cold, but it was mind over matter," said running back Eddie Lacy, who also went without long sleeves. "We did a great job of dealing with it from a mental aspect, so it wasn't too bad."
The coldest NFL game on record is the 1967 championship game, known as the "Ice Bowl" won by the Packers 21-17 over the Dallas Cowboys at Lambeau Field on New Year's Eve. The temperature dipped to minus-13, and the wind chill that day was minus-48.
The game at 80,000-plus capacity Lambeau Field was sold out. But with tailgating more subdued because of winter's blasts fans, had to find other ways to celebrate before the showdown between the NFC rivals.
Some fans took to unusual measures to stay warm. At one house two blocks from Lambeau, revelers dressed in camouflage outdoor gear and gathered next to a fire pit set up in the driveway.
Greg Falkenberg and wife Laurie of Chippewa Falls went through all but two cans in a case of beer about 90 minutes before kickoff. They thought the alcohol could help keep them warm.
"You know beer in the cereal is good for you," Falkenberg joked.
And no, cold would not be factor for them.
"Absolutely not," Falkenberg said. "This is the Frozen Tundra."