HOUSTON (November 5, 2011)—Nearly two-dozen people, many of them students, became ill during a high school football game Friday night in Houston after they were exposed to an unknown substance.

The Houston Fire Department sent HAZMAT crews Friday night to Barnett Stadium in southeast Houston after Austin High band members became ill during a game against Yates.

A Houston school district spokesman told the Houston Chronicle that symptoms included severe nausea, dizziness and vomiting.

Herbert Griffin, an assistant fire chief, said whatever students were exposed to came from the concessions area.

In all, 22 students from the band and drill team were taken to five Houston hospitals.

A firefighter who complained of nausea remained at the stadium to treat students.

The game was ended early and the stadium was evacuated.

A game scheduled to be played at the stadium Saturday was moved because of the incident, the Chronicle reported Saturday.