49ers were greeted by deafening temperatures in Colorado

AIR FORCE ACADEMY, Colo. – Three days before the January 2012 NFC Championship game, then-San Francisco 49ers head coach Jim Harbaugh was pleased that rain was forecast for practice that day as precipitation was expected at the game.

“If you’re going to fight in the North Atlantic,” Harbaugh said, quoting a former admiral, “then you have to prepare in the North Atlantic.”

Ten years later, the 49ers are actually doing something completely different: preparing for a game in the South Pacific in the North Atlantic.

The 49ers held their first high-altitude practice at the Air Force Academy Thursday in preparation for their high-altitude meet Monday night against the Cardinals in Mexico City.

The weather conditions at the start of training in Colorado: 21 degrees with light snowfall. The conditions at the same time in Mexico City: 74 degrees and partly cloudy.

Is head coach Kyle Shanahan concerned about preparing for a game at an outdoor stadium in a warm-weather city in sub-zero temperatures? He hinted that the 49ers would thaw well before kickoff on Monday.

“I think the cold is a kind of pain,” Shanahan said. “I don’t like being cold. But in practice it has not changed anything. So it hasn’t been any different up to now.”

The 49ers, who arrived in Colorado Springs on Tuesday, will hold three drills at the Air Force Academy (altitude: 6,788 feet) to acclimate to the high altitude. They will play at the Estadio Azteca on Monday, which is 7,218 feet above sea level.