Some of the people who attended the near-record cold Kansas City Chiefs playoff game in January had to undergo amputations after suffering frostbite, a Missouri hospital said Friday.

Research Medical Center didn’t provide exact numbers but said in a statement that it treated dozens of people who had experienced frostbite during an 11-day cold snap in January. Twelve of those people — including some who were at the Jan. 13 game — had to undergo amputations involving mostly fingers and toes. And the hospital said more surgeries are expected over the next two to four weeks as “injuries evolve.”

The University of Kansas hospital said it also treated frostbite victims after the game but didn’t report any amputations.

The temperature for the Dolphins-Chiefs wild-card playoff game was minus 20 Celsius, and wind gusts made for a windchill of minus 33 C. That shattered the record for the coldest game in Arrowhead Stadium history, which had been minus 17 C, set in a 1983 game against Denver and matched in 2016 against Tennessee.

The wild-card game was played the same day the Buffalo Bills were supposed to host the Pittsburgh Steelers, but that game was pushed back a day because a blizzard dumped more than half a meter of snow in New York and made traveling to the game too dangerous.

The game in Kansas City went on as scheduled because the frigid weather didn’t present similar problems getting to Arrowhead Stadium, even though the National Weather Service warned of “dangerously cold” windchills.

Frostbite can occur on exposed skin within 30 minutes, Dr. Megan Garcia, the medical director of the Grossman Burn Center at Research, said in a statement that answered one of the top questions she is asked. The timing can be even shorter if there is a windchill, she said.

Fans were allowed to bring heated blankets into the stadium and small pieces of cardboard to place under their feet on the cold concrete.

The coldest game in NFL history remains minus 25 C for the 1967 NFL championship, when the Packers beat the Cowboys at Lambeau Field in a game that came to be known as the Ice Bowl. The windchill that day was minus minus 44 C.

The Chiefs didn’t immediately respond to email messages from The Associated Press seeking comment.