The Grand Valley Community Centre remains closed after a carbon monoxide leak late Sunday afternoon. 

Several people were taken to hospital for treatment following a carbon monoxide leak at the arena.

Dufferin County paramedic Jason Dzikowski was playing hockey at the arena when some friends started to feel weak and dizzy.

"I asked who is feeling awful right now, how are you feeling? they all said fatigued, light headed dizzy one gentleman thought he was going to pass out. I knew something wasn't right there,” said Dzikowski.

Dzikowski called a fellow paramedic who happened to be working next door and asked for a portable carbon monoxide detector.

"Right away this portable carbon monoxide detector went off," he said.

Emergency crews responded to the Grand Valley Community Centre. Fire crews say people inside were starting to feel dizzy, nauseous, and had headaches.

Crews immediately evacuated the building and began ventilating. They later confirmed high levels of carbon monoxide in the building. 

More than a dozen people were taken to Headwaters Hospital in Orangeville for treatment, their conditions are still unknown. Another twenty four people were treated on scene.

The town says their symptoms are minor, but still advised anyone who was at the arena and experiencing symptoms of carbon monoxide poisoning should seek medical attention.

County officials say Dzkowski's actions saved the day.

"His training and experience kicked in, allowed him to identify the situation that was a risk to the public, He took charge of the situation and is responsible for the positive outcome that we did see," said Steve Murphy Dufferin County emergency coordinator.

Town officials haven't identified the source of the carbon monoxide.

"Hopefully we can track it down, they tried a few different things but couldn't find a spike," said mayor Steve Soloman.

The building, including the arena and daycare centre inside, will remain closed until further notice.

- With a report from CTV Barrie's Roger Klein.