It appears as though they were affected by carbon monoxide, possibly from the school bus that they rode while traveling to Polson, he said.
"We provided them with medical support and they were transported to the hospital," he said.
Here is additional information from the Madison Police Department:
On October 23, 2013 at 1638 hours, Madison Emergency Communications received a 911 call regarding as many as 12 patients suffering from difficulty breathing related to possible carbon monoxide exposure near Polson Middle School, 302 Green Hill Road, Madison. The patients are members of the North Haven Junior Varsity Girls Soccer Team. The patients played approximately half of the soccer game before they began to shows signs of possible carbon monoxide exposure.
At least 8 juvenile patients and 1 adult patient have been transported to local hospitals. The suspected source of the exposure is a school bus owned by M&J Company, 12 Quinnipiac Avenue, North Haven, Connecticut. The bus driver has been contacted, and is not currently showing any signs of possible carbon monoxide exposure.
Multiple Madison Police Officers and three Madison Ambulance Association units responded immediately to the scene. Due to the number of potential patients, mutual aid was requested. Guilford Ambulance responded by sending 3 EMS Units to the scene.
The condition of the transported patients is not currently available.