(AP) — School officials say lunchtime dares to drink a weird concoction that included hot sauce, carrots, salt and milk likely caused 22 students to get sick at a San Diego elementary school — if all of them were actually ill.

San Diego schools spokesman Jack Brandais says Friday that children at Audubon Elementary dared each other to drink from the mixture Thursday. Some reported upset stomachs and nausea afterward.

Teachers then made a general announcement to see if other students had stomach problems. Brandais says that call brought out students “who may not have had problems at all.”

Of the 22 students, 18 were taken to the hospital, and all were later released.

As a precaution, the school’s kitchen, cafeteria and outdoor lunch areas were sanitized overnight.