Women’s hockey players from the University of Wisconsin and Lindenwood (Mo.) University suffered carbon monoxide poisoning during a game on Friday. The ice arena they were playing in has been closed until the issue can be resolved.

According to ozarksfirst.com, a member of the Wisconsin team left for the hospital with complaints related to carbon monoxide poisoning prior to the game ending. After the game, some Lindenwood players drove themselves to the hospital and received oxygen treatments on their own as a precaution.

From ABCarbon Monoxide Leak at Rink Sends 81 to Hospital

Scott Queen, the executive director of marketing and communications for Lindenwood, said that it’s unknown whether any spectators received treatment on their own.

The facility reportedly tested for levels of carbon monoxide far beyond what’s considered high. A high level of CO measures at a level of 10, but the Lindenwood facility measured at a level of 200.

From AB: Carbon Monoxide Scares Shut Down Two Ice Rinks

At first, it was thought that malfunctioning humidifiers were responsible for the high levels of CO, but officials now believe that a malfunctioning ice resurfacer is to blame.

An investigation into the incident is ongoing.

Jason Scott is Online Managing Editor of Athletic Business.