PHILADELPHIA – The college ice hockey team jumped to a quick 3-0 lead but then appeared sluggish, some players coughing and some woozy. The team ended up losing 11-5.

The next day, 18 players and their coach showed up at a hospital emergency room with breathing problems. State health officials and the federal Centers for Disease Control and Prevention launched an investigation.

The players were apparently sickened by carbon monoxide and nitrogen dioxide fumes seeping into their locker room. A malfunctioning Zamboni machine resurfacing the rink during breaks in the game is suspected as the cause.

Fumes such as the ones that struck the Millersville University players in a Sept. 29 game with Lafayette College in Whitehall, near Allentown, pose a hidden potential danger at hockey and figure skating competitions all over the country.

Public health officials say such fumes can build up if the Zamboni machines malfunction or if the arenas are not well-ventilated. But even some participants who are on the ice every day are unaware of the potential danger.

Awareness is especially important because of the rising popularity of hockey and skating, officials said. The number of children playing hockey has more than doubled over the past decade to more than 360,000, according to USA Hockey spokeswoman Heather Ahearn.

And skaters are usually unaware of the danger, since fumes from ice resurfacers usually are odorless.

Clean-air rules are required in ice arenas in only three states: Massachusetts, Minnesota and Rhode Island, where operators are required to test for buildup of exhaust fumes and to evacuate their arenas if levels are high.

There are an estimated 1,700 ice arenas in the United States, and busy rinks use machines many times a day. Most are powered by gasoline or propane engines that produce carbon monoxide and nitrogen dioxide gases in their exhaust.

Health and industry authorities say without proper venting in ice arenas, an ice resurfacer is comparable to a car running inside a closed garage.

In recent years, Zamboni and other manufacturers have begun making electric-powered ice resurfacers that produce no exhaust. But industry officials say those machines are more costly, and it may be a long time before they are widely used.