By Steve Silverman–

(CBS) — The San Francisco 49ers are going to get tested by the elements in Green Bay, perhaps more so than they will by the Packers.

San Francisco has proven it can beat Green Bay. The 49ers rolled past Green Bay in the 2012 season opener, the 2012 playoffs and this year’s season opener. The Packers don’t have the defensive strength to handle Colin Kapernick, Frank Gore and Anquan Boldin.

However, the 49ers have no idea if they will be able to handle the sub-zero temperatures that are expected to envelop northern Wisconsin by the time the game kicks off at 3:40 p.m. The Weather Channel says temperatures could reach minus-19 degrees and describes the environment as “life-threatening cold.”

This is not a matter of what head coach Jim Harbaugh says to his team before kickoff, or how badly the 49ers – or Packers, for that matter – want to win. It’s a matter of survival.

The wild-card game between the Niners and Packers will be Ice Bowl II. The first Ice Bowl is one of the NFL’s most legendary games. The visiting Dallas Cowboys, coached by Tom Landry and led by quarterback Don Meredith and defensive tackle Bob Lilly, came to Green Bay to play for the 1967 NFL championship on New Year’s Eve.

While the game was played at high noon, it was still minus-13 degrees. The two teams played a sensational game on a frozen Lambeau Field. Packer Hall of Fame quarterback Bart Starr scored the game-winning TD when he followed guard Jerry Kramer’s block and scored on the game’s final play.

The Packers won the NFL championship 21-17 and went on to defeat the Oakland Raiders 33-14 in Super Bowl II.

There have been many other cold-weather games since then, and the 49ers will find out how they react to this brumal environment. If they can survive this game, the 49ers may be in the best position to come away with a victory in Super Bowl XLVIII.

The 49ers are going into the postseason as the NFL’s hottest team. They have won six games in a row, and that’s a longer streak than any of the higher seeds in the playoffs that don’t have to play during the wild-card weekend.

While Denver, New England, Seattle and Carolina are all formidable opponents, all of those teams have potential weaknesses that could be their undoing. Additionally, lower-seeded teams that played in the first round of the playoffs have won the last three Super Bowls and five of the last seven.

Denver looks like one of the NFL’s all-time great teams because their offense has been so prolific this season. The Broncos scored a record 606 points, while Peyton Manning threw 55 TD passes and was simply unstoppable.

However, the Broncos are quite vulnerable on defense. They ranked 19th overall and were 26th against the pass. If the Broncos turn the ball over two or more times, that defense may not be able to hold up and the Broncos could disappoint in the postseason, just as they did last year when they were upset in the divisional playoffs by the Ravens.

The Patriots won the AFC East and finished as the No. 2 seed in the conference, but this is not a strong team. The defense became vulnerable when it lost defensive tackle Vince Wilfork and linebacker Jerod Mayo earlier in the season. Wilfork and Mayo are the Patriots’ two best defensive players, and they can’t stop the run without those two studs. If it was not for cornerback Aqib Talib, they Pats would not be able to defend against the pass, either.

Offensively, the Pats survived the stretch run without tight end Rob Gronkowski, but they will not be so fortunate in the playoffs. Yes, they have Bill Belichick and Tom Brady, but the Patriots are simply not good enough to win this year.

The Seahawks looked like the best team in the NFL for the large majority of the season. Offensively, the combination of quarterback Russell Wilson and running back Marshawn Lynch were formidable. While they have been consistent for the majority of the season, Wilson has cooled off down the stretch and has thrown just four TD passes in his last four games.

The Seahawks’ strength is their defense, but they are much stronger on the back end with cornerback Richard Sherman and free safety Earl Thomas than they are up front. If the Seahawks don’t get a formidable pass rush, Sherman and Thomas can’t do it by themselves.

The Panthers have been thoroughly impressive, winning 11 of their last 12 games. They have a tremendous 1-2 defensive punch with defensive end Greg Hardy and middle linebacker Luke Kuechly, but they also have Cam Newton at quarterback.

Newton is a special athlete who can take over a game and dominate. But he can also miss short- and medium-range throws that high-level NFL quarterbacks are expected to make. He can be spectacular, but he lacks consistency.

That’s why the Niners appear to be in good shape. They have offensive versatility and one of the hardest hitting defenses in the league. NaVorro Bowman is a near-perfect tackler who does not make errors, while Ahmad Brooks and Aldon Smith will get after the quarterback.

The 49ers are fueled by their loss in last year’s Super Bowl, and if they can survive the truly frozen tundra, they will get a chance to lift the Lombardi Trophy next month.

Steve Silverman is an award-winning writer, covering sports since 1980. Silverman was with Pro Football Weekly for 10 years and his byline has appeared in the Wall Street Journal, Playboy, and The Sporting News. He is the author of four books, including Who’s Better, Who’s Best in Football — The Top 60 Players of All-Time. Follow him on Twitter (@profootballboy) and read more of his CBS Chicago columns here.

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