For professional sports, climate change could create a whole new ball game

On Jan. 13, a winter storm walloped most of the U.S., bringing dangerously cold winds, freezing rain, heavy snow and near-record lows in some areas.

The extreme weather also packed a punch for a few professional sports teams.

In Buffalo, itsNHL and NFL teams both rescheduled games, citing the safety of fans and players. In Kansas City,however, a planned bout between the Chiefs and Miami Dolphins went aheaddespite temperatures reaching 30 C withthe windchill. That game hit the record books as the fourth-coldest in NFL history, with casualties including frostbite, hypothermia and a busted helmet.

Cold snaps aren't unusual in North America, even with Earth seeingrecord high temperatures.Steve Easterbrook, director of the University of Toronto's School of the Environment, says the boundaries of the polar vortex are held by the jet stream. But as the poles warm up faster, the jet stream getsweaker.

That means sudden blasts of Arctic air may occur more frequently, with the impacts felt ever further south.

For professional sports teams, how might that change the game?

Broken helmet, deflated balls

During the Chiefs game, quarterback Patrick Mahomeslost a piece of his helmet when it broke off after a head-to-head hit with one of the Dolphins. The extreme cold was believed to be a contributing factor.

Helmet manufacturer VICISreleased a statement on Xa few days after the game, saying, "Extreme conditions like those experienced in Saturday evening's NFL playoff game are bound to test the limits of even the highest performing products."

John Eric Goff, a professor of physics at the University of Lynchburg in Virginia, says the damage could have been caused by temperature difference between the inside and outside of the helmet.

"The outside might be contracting more than the inside is and that could lead to instability and breakage," he said.

Cold weather also affects the air pressure of inflatable balls, including those used in football and soccer.As Goff explains, "Pressure roughly scales with the temperature and as the temperature goes down, the air pressure can go down for a given volume of air inside the ball."

NFL rules dictate game balls must have pressures between 12.5 and 13.5 pounds per square inch. When ball pressure goes down, it becomes easier to grip.

Soft balls were the issue in the so-called "Deflategate" scandal when formerNew England Patriots quarterbackTom Brady was accused in 2015of deflating footballs during the 2014 AFC Championship Game.

Some people argued that air temperature could have been the real culprit. The temperature was about 11 C during the game against the Indianapolis Colts.

Goff notes that cold weather can have other impacts on a football game. It impacts anathlete's ability to grip the ball, while higher air drag means the ball may not travel as far as it would on a warmer day.

Sports likesoccer arealso affected bythe cold. "The headers, the kicks, the free kicks. All these things are going to go down in speed and distance whenever the air gets a lot colder," says Goff.

Hypothermia, frostbite and injury risks

Cold temperatures pose health risks for athletes and fans in stadium stands.

On Jan. 13, 10 fans went to hospital in Kansas City seeking treatment for hypothermia and frostbite.On the field, many players did not wear extra layers.

"Hey, look man, it's a mindset. Those guys see you wearing sleeves, obviously they gonna think you soft," Tyreek Hill, a Dolphins wide receiver told reporters.

But at what point does it actually become dangerous to play in these conditions?

WATCH | Former NFL player recountsthe 60C'Freezer Bowl' in 1982:

Remembering the Freezer Bowl

10 months ago

Duration 6:43

After an NFL playoff was cancelled due to extreme weather - snow and cold - we looked back at the time a wind chill approaching minus 60 degrees didn't keep the players from lining up. Former Cincinnati LB Glenn Cameron played in what became known as "The Freezer Bowl," and shares his memories with CBC News Network's Hannah Thibedeau.

In a 2015 article published on NFL.com,Dr. Matthew Matava the then-president of the NFL Physicians Society and longtime team doctor for the now-defunct St. Louis Ramsexplained some of the risks to players when the weather gets cold.

"Players will be at an increased risk for muscle strains and tears, usually to the hamstrings, quadriceps and calf muscles," he is quoted as saying. "Since the ball is harder, there is a risk for fractures of the hand and fingers when trying to catch or receive the ball."

The risk of hypothermia begin once temperatures dropped to between5 and 10 C, saysMadeleine Orr, an assistant professor of sport ecology at the University of Toronto. Athletes are at a higher risk due to their restrictions in uniform.

Slick fields and frozen soil also put athletes at risk of more serious injuries, she says.

There are serious long term risks as well, she adds. "If you get frostbite, you could be losing sensation in your fingers or whatever part of your body for a prolonged period of time, potentially indefinitely."

Are outdoor stadiums sustainable?

In December 2010, the fabric roof of Minnesota's Metrodome, home of the NFL Vikings, collapsedat 5 a.m. on a game day under the weight of snow that had accumulated during Minnesota blizzard. Two games were relocated; eventually the facility was replaced.

Last yearin England, a Women's Super League soccer gamewas suspendeddue to a frozen field. Last week, the Kamloops Soccer Dome was closed because it is not fully insulated or safe for players during extreme winter conditions.

Indoor stadiums would eliminate many weather-related impacts. But it would also steal memory-making weather games from the fans.

WATCH | Bills fans have fun while shovelling snow:

Shirtless Buffalo Bills fan slides down snow chute while shovelling out football stadium

10 months ago

Duration 0:23

A rambunctious Buffalo Bills fan took a break from shovelling at Highmark Stadium in Orchard Park, N.Y., this weekend to rip off his shirt and slide down a chute meant for snow. He was one of several fans who showed up to help stadium staff clear the 70,000-seat facility ahead of Monday's game against the Pittsburgh Steelers. (Submitted by Eric Shields)

For Buffalo Bills fans, shovelling snow out of the stands is a tradition.On Jan. 15, hundreds of fans showed up to prepare Highmark Stadium for the game.

But Orr wonders if these types of special moments outweigh the risks.

"There's going to have to be a kind of a frank discussion happening in every professional sport that plays in these big outdoor stadiums about how do we better prepare to be adaptive?" she says.