École secondaire L'Odyssée-des-Jeunes, a Laval high school, was evacuated Wednesday morning due to the presence of carbon monoxide. Several people were transported to the hospital with minor issues. According to a spokesperson from Urgences-Santé, a call came in at 8:39 a.m. because of a "suspicious odour."\nThere were 18 patients under the age of 18 and another three adults transported to a local hospital due to carbon monoxide inhalation. Students and staff reported feelings of dizziness during the early morning hours.\nAll injuries were minor and there are no serious complications, according to Urgances-Santé.\n"We deployed two supervisors on-site, seven ambulances, and a supply truck to help with the patients," said the spokesperson. Reports indicate that the carbon monoxide leak came from an error in the school's heating system.\nThe incident ended at around 11:40 a.m. Wednesday morning once the carbon monoxide levels reached zero. Urgence-Santé's spokesperson tells MTL Blog that firefighters have let people back inside the building.\nEvacuated students were sent to surrounding libraries or schools while the situation was being handled by local authorities.\nÉcole secondaire L'Odyssée-des-Jeunes houses roughly 1,000 elementary and secondary students.\n"Carbon monoxide can cause health problems before you even notice that it's present," says the government of Canada.\n"Breathing it in reduces your body's ability to carry oxygen in your blood."\nGoogle Maps\n"At low levels, effects include flu-like symptoms, such as tiredness, headaches, shortness of breath, and impaired motor functions."\nExposure to high levels of carbon monoxide can result in convulsions, coma, and even death.\nThis is a developing story. This article will be updated.