You've probably heard the term "six degrees of separation."
That's about two degrees more than the forecast for Sunday's NFC playoff game between the Seattle Seahawks and Minnesota Vikings in Minneapolis.
It is the Vikings' first outdoor home playoff game in 39 years, and frigid weather is expected. Even hardy Minnesotans seem apprehensive, with tickets available on the secondary market for less than $50 -- much cheaper than this weekend's three other wild-card matchups.
Sunday's expected high temperature of 4 degrees would mark the coldest home playoff game in the history of the Vikings, a team that played outdoors at Metropolitan Stadium from 1961 to 1981 and at the University of Minnesota's TCF Bank Stadium in 2014 and 2015.
Next season, the Vikings will move into the sparkling new U.S. Bank Stadium, an indoor venue. So barring a series of upsets that would allow the Vikings to host the NFC Championship Game on Jan. 24, the team doesn't expect to be playing another outdoor home game anytime soon. There will be no frozen tundra Sunday. The Vikings paid to have a heated field installed in 2014, and tarps will cover the playing surface until game day to keep out moisture.
Despite the forecast, the visiting Seahawks are favored by five points.
What oddsmakers might not know is that the Vikings could have a distinct advantage in occupying the north sideline Sunday. They will receive far more sunlight than the Seahawks, who will be positioned on the south sideline. The temperature difference between the two sidelines was a significant 20 degrees at a recent game.
That could be important with winds expected from the west at up to 10 mph, which would equate to a wind chill of minus 16.
With all of the above in mind, here are 10 more things you should know about the Seahawks-Vikings tilt and frigid football in general:
First, a bit of history
Dan Reeves grew up in Georgia and played college football at South Carolina, but few people can speak with greater authority on the subject of frigid football.
He played in the Ice Bowl as a running back for the Dallas Cowboys. He coached the Denver Broncos and New York Giants for a combined 16 seasons and was at the helm when the Atlanta Falcons became the first road team to win a playoff game at Lambeau Field in January 2003.
The cotton gloves the Cowboys wore at the aforementioned 1967 NFL Championship Game are a far cry from current innovation. They were a detriment to handling the football, whereas today's gloves greatly enhance grip. Dallas coach Tom Landry didn't allow any player who might handle the ball to wear gloves, and Reeves said the ball felt like a brick while he was holding for kicks in pregame warm-ups. So when a halfback option pass was called on the first play of the fourth quarter, Reeves had to figure out how regain sensation in his fingers.
"I put my hands down in my pants as far as I could put 'em in the groin area," Reeves said with a laugh. "We shifted from I-formation, and I shifted over to the left [in a split backfield]. At the last second, I took my hands out of my pants. Because I knew I had to throw the football, and I've gotta be able to feel that thing. So that was my equipment."
Reeves threw a 50-yard touchdown pass to Lance Rentzel to give Dallas a lead that lasted until the final minute of the game, when Packers quarterback Bart Starr famously scored the winning touchdown on a 1-yard sneak.
Reeves, 71, also was a member of the Cowboys team that beat the Vikings 20-12 in a divisional playoff game at Metropolitan Stadium on Christmas Day in 1971. He recalls Vikings players loitering near the Cowboys bench before returning to their own bench after drives in order to get a quick blast from the heaters that tough-minded Minnesota coach Bud Grant banned in his team's area.
"That was when both teams were on the same side of the field," Reeves said. "I remember we had the coats pulled over us. Bud Grant didn't let his players wear the capes. We'd look over there and those guys would just be standing there with short-sleeved shirts on."
Regardless of equipment, Reeves said the key to succeeding in harsh conditions isn't physical. As the Falcons prepared to visit Green Bay in 2003, he told his players to narrow their focus in order to keep a mental edge.
"Don't worry about the weather," Reeves said. "Handle it better than the guy across from you. That's your focus. Just handle it better than he does."
Each of the three coldest matchups in NFL history were postseason games with kickoff temperatures below zero degrees Fahrenheit.
Best seat in the house
Perhaps the greatest innovation in the annals of frozen football is the heated bench.
You've probably seen players enjoying this piece of thermal furniture, sitting in warmth with their helmets behind them atop heated posts. Teams typically use four to six of these benches per sideline, and they seat six to eight players each.
Frank Floyd invented the heated bench, and his Dragon Seats firm supplies them to 18 NFL teams and many college football programs. The University of Minnesota is a Dragon Seats client, and the Gophers' benches will be used on Sunday by the Seahawks and Vikings.
Floyd provided sideline heaters to the old Cleveland Browns in the 1990s before the team moved to Baltimore. When the Browns were revived in 1999, Floyd offered his services to the team. Cleveland's equipment manager at the time, Bobby Monica, wondered if there was heated equipment on which players could sit. That's when the light bulb went on for Floyd.
"I drew a picture on a piece of paper, sitting across the desk from [Monica], of exactly what is on the sideline right now -- a hollow bench that is 12 feet long and ergonomically designed to fit a 300-pound football player," Floyd said.
He visited the Browns facility in Berea, Ohio, to measure players so that the benches could accommodate even the largest of linemen. By the fall of 1999, the first iterations of the Dragon Bench were in use at Browns games. Word quickly spread among NFL equipment managers, and the units became prevalent around the league within a few years.
In addition to a comfortably heated surface and heated helmet posts, the fiberglass benches have rear doors that can be opened to store and heat equipment, such as gloves. There is also a narrow drawer that can be pulled out in front of the unit that blows heat upward. Players can then stand on the drawer and absorb the warmth.
"We became a licensed supplier of the NFL, and that doesn't happen unless you have a quality product," Floyd said. "The original units that we issued [to the Browns] 16 years ago are still on the sidelines."
Floyd also supplies teams with high-powered blower heaters, most of which run on propane or natural gas. If the air temperature is zero degrees, the air coming out of these units will be about 150 degrees. They have protective shells that make them safe to the touch and can heat 10 to 25 people at once.
In a nutshell, while players and coaches won't exactly be enjoying the comforts of a luxury suite, they will have a much easier time staying warm than the vast majority of fans at Sunday's game.
Including the postseason, these four quarterbacks have started the most games in the past 15 seasons when the temperature was a freezing 32 degrees or lower.
Each has a winning record: Brady is 28-7 (.800); Roethlisberger is 19-7 (.731); Favre is 13-12 (.520); and Rodgers is 17-5 (.773).
Take care of the hands team
In addition to wrapping their cores with layers upon layers of cold-weather gear, players will pay special attention to their extremities. The Seahawks and Vikings are likely to burn through hundreds of packets of hand warmers and foot warmers.
NFL players at skill positions have worn pouch-style hand warmers since the 1980s, and the latest versions are sleek and effective. (Uni Watch's Paul Lukas recently explained this topic in depth.) Minnesota quarterback Teddy Bridgewater and Seattle quarterback Russell Wilson regularly use pouches and almost certainly will utilize them Sunday.
Taking it a step further, the gloves available to players today provide amazing grip, as any Odell Beckham Jr. highlight reel will attest. Bridgewater almost always uses gloves, regardless of weather, so he will be in his usual element in this regard. Wilson, however, prefers to go without gloves. Unless he rethinks that preference, expect him to rely on a pouch stuffed with hand-warming packets.
(For a detailed look at the evolution of football gloves, check out this video segment by ESPN's Jim Trotter.)
Wilson vs. Bridgewater
Including the postseason, Wilson has played in 72 career NFL games. He lost the only one with a kickoff temperature of 32 degrees or lower -- 24-20 at Kansas City in Week 11 of 2014. Conversely, Bridgewater has gone 3-2 in five such games during his two NFL seasons.
Chicken broth, warm tea and Vaseline
ESPN analyst Antonio Pierce is another person who can speak to playing in extreme cold. He was the starting middle linebacker for the Giants when they won 23-20 in overtime at Green Bay in the 2007 NFC Championship Game. With a kickoff temperature of minus 1 degrees, it is the third-coldest NFL game on record.
"It was the first game I never wanted to drink water or anything," Pierce said. "We had chicken broth and warm tea on the sideline. Normally, you wouldn't even think about having that during a game."
One of the lasting images of that game was the bright-red face of Giants coach Tom Coughlin, and Pierce said players feared he would sustain frostbite. It wasn't until later that they learned a product applied to Coughlin's skin had enhanced the reaction.
As far as the best secret for beating the cold, Pierce said he learned that in Washington from Hall of Fame defensive end Bruce Smith, who played 15 seasons with the Buffalo Bills.
"Before cold games, he would get a big jar of Vaseline and just use it on his whole body," Pierce said. "That clogs up your pores, so that keeps the warmth. Now, the only thing is at halftime you're going to have to do it again. You've got to take your uniform off, your shoulder pads and all that stuff, and do it all over again."
To wit, Pierce described a pregame scene of Smith -- wearing nothing but a jock strap -- being slathered from head to toe in petroleum jelly by trainers.
Thanks for the image, Antonio.
Coldest recent playoff games
Three postseason games have been played in the past 15 years with kickoff temperatures in the single digits.
The coldest football game in the history of TCF Bank Stadium, which opened in 2009, was the matchup between the Vikings and Carolina Panthers on Nov. 30, 2014. The kickoff temperature was 12 degrees, which was 3 degrees colder than when the University of Minnesota played host to Ohio State on Nov. 14, 2014.
Colder than each of those games, however, was the Ohio State-Minnesota hockey game at TCF Bank Stadium on the night of Jan. 17, 2014. The temperature was 10 degrees when the puck dropped and later dipped into single digits with a subzero wind chill.
Gophers hockey coach Don Lucia didn't think the conditions were too bad, though. Players layered up and used Dragon Benches, and the Plexiglas boards reduced wind chill. Lucia traded his sport coat and tie for a heavy jacket, beanie, heated socks and boots. By contrast, Lucia thought the previous day's weather was much worse.
"I remember the practice being cold the day before, because the wind was whipping pretty good," he said. "It was coming in from the northwest into the open end of the stadium."
That's the same direction the wind is expected to blow Sunday on the Seahawks and Vikings.
Lucia grew up in Grand Rapids, Minnesota, and is a lifelong Vikings fan who recalls crying when the team lost Super Bowl IV to the Kansas City Chiefs. Pointing out the availability of relatively inexpensive tickets for the playoff game, Lucia wonders if Vikings supporters are less rugged than those of yesteryear.
"I think the fans have become softer," Lucia said. "I still think the stands will be full. Obviously, there's excitement, especially when you go into Green Bay and can beat your archrivals on the road to clinch the division."
For the record, Lucia predicts Adrian Peterson will have a big game and lead the Vikings to a 20-17 victory over the Seahawks.
Unprotected skin can be susceptible to frostbite in half an hour when the wind chill is minus 20 degrees. Sunday's weather in Minneapolis could approach that figure. Stay warm out there.