Fly poison is generally a volatile toxic substance, if inhaled in large quantities will be poisoned. The first symptom of poisoning is respiratory symptoms, because the inhalation of harmful substances will stimulate the throat or airway, resulting in nasal and pharyngeal dryness and pain or irritating cough, asthma can be asthmatic attack. If the bronchial tubes or larynx are irritated, causing laryngeal edema or pulmonary edema, dyspnea may occur. Neurological symptoms, there will be dizziness, headache, nausea, vomiting, mental inattention or uncoordinated arms and legs, serious cases may also appear blurred consciousness, coma, convulsions, shock and other symptoms, the most serious may be central respiratory failure and lead to death.