Amid the furor over concussions in the NFL, a new study finds that players are at a higher risk for the injuries during games played when it's colder out. Researchers looked at injury report data from all 32 NFL teams for the 2012-13 and the 2013-14 regular seasons, and found that during games played in temperatures of 50 degrees Fahrenheit or lower, players had double the risk of concussions compared to those in games played at around 70 degrees or warmer. There was also a 1.5 times higher risk of ankle injuries in the colder games, and a 1.36 times higher rate of shoulder injuries for players in games on natural grass (as opposed to synthetic turf), UPI reports. The Canadian researchers say this is the first study to show such a link with the weather, notes the Toronto Globe and Mail.
The study did not identify why the higher risk exists, but "at colder temperatures, materials and equipment in the playing environment have a lower elastic potential, and that may increase the impact forces that are transmitted during the game and increase forces to the head," the lead author says. It's also possible that concussions are simply under-reported for games at warmer temperatures, since players might incorrectly believe they are simply dehydrated or overheated. During colder games, athletic staff might be more quick to realize concussion symptoms, because they are interacting with players more often to keep them warm on the sidelines. As for the ankle injuries, the lead author says it's possible bodily reflexes don't work as well in the cold, making injuries more likely. (A new report on the NFL's concussion research is quite damning.)