Anaphylaxis is a severe, potentially life-threatening allergic reaction that can occur within seconds or minutes of exposure to an allergen. Common triggers include foods (especially peanuts, tree nuts, and shellfish), insect stings, medications, and latex. Symptoms include difficulty breathing, swelling of the throat, rapid heartbeat, dizziness, and a dramatic drop in blood pressure. Anaphylaxis requires immediate treatment with epinephrine (often carried in auto-injectors like EpiPens) and emergency medical care. Canadian schools and public spaces increasingly have policies requiring awareness of severe allergies and availability of emergency epinephrine.