Officials say it happened around 2 p.m. Sunday at an ice rink in Gunnison.
Randy Phelps, chief executive officer at Gunnison Valley Health, says eight people had serious amounts of carbon monoxide in their blood.
He says six other people were being treated at Gunnison Valley Health. The rest of the victims were treated and released.
Two victims were transported to Denver for hyperbaric chamber treatment, but have also been released.
One of those treated was Lauren Johnson. Lauren's mother Judy said there was a heavy smell of fumes in the arena from the gas powered zamboni.
Judy Johnson said several parents in the stands were complaining about the smell and had headaches. However, what concerned her most was the players on the ice, she said it was like watching a game in slow motion.
"We thought they gave up because they were losing," Johnson said. "But I have never seen a game where they were that slow and lethargic, both teams."
There is no word on what may have caused the carbon monoxide leak. The ice arena is closed until further notice. The Gunnison Fire Department is spending the day inspecting the ventilation system in the building.
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