On April 6, 2012, 11 children from three different classes at an elementary school in the Nord department experienced mild and transient digestive symptoms (vomiting, abdominal pain, diarrhea) or nonspecific symptoms (headaches). The possibility of exposure to a toxic substance was raised, as a detergent-like odor had been detected in a classroom. The SDIS (Departmental Fire and Rescue Service) and SMUR (Emergency Medical Assistance Service) responded, and some of the children were taken to the emergency room at the Douai Hospital Center. No obvious cause was found, and the symptoms quickly disappeared. On April 12 and 13, six children again presented with similar symptoms, with no underlying cause identified. Epidemiological and environmental investigations found no objective evidence of exposure to a toxic substance. It is plausible that some children experienced symptoms related to a mild episode of acute gastroenteritis; the simultaneous perception of a detergent odor may have caused concern and led to minor complaints in other children. The scale of the resources deployed during the initial response, which raised legitimate concern, likely contributed to amplifying and perpetuating this phenomenon in some children. (R.A.)