SANTA CLARA, Calif. -- The arctic conditions awaiting the San Francisco 49ers in the wild-card round at Green Bay is the theme of the week.The game-time temperatures are expected to be as low as minus-20. However, it's not the weather per se that has 49ers coaches concerned. It's the field conditions."To me it all depends upon what the footing's like," said San Francisco defensive coordinator Vic Fangio when asked if the weather could affect the game plan.