Beterem, the National Center for Child Safety and Health, advises parents, teachers and caregivers to promote the joy of Purim while avoiding its dangers. Every year dozens of children are injured by flammable costumes, explosives and swallowed foreign bodies. The holiday, marked by festive dinners, reading of the Book of Esther, masquerading and the sending and receiving of gift parcels, begins on Monday night in most of the country and on Tuesday night in Jerusalem and other ancient walled cities. Beterem warned against using any firearms or pistols that look like the real thing, firecrackers, caps, missiles or other explosives that can injure the eyes, ears and skin. Do not purchase Purim toys, costumes and makeup from street vendors, but only from established retailers and with safety approval from the Health Ministry on them. Avoid spray foams, and never aim them at the eyes, which can suffer damage. If spray gets in the eyes, wash it out immediately with lots of cold water. Purim costumes should not include feathers, cotton wool, paper or other flammable materials. If a costume is set on fire, Magen David Adom advises laying the child on the ground and rolling him in sand or earth, putting out the fire with water or smothering the flame with a wet blanket. Do not cover the victim's head, pull burnt clothing from the skin or apply ointments. Take the victim for medical treatment. Costumes should not cover the heads of children so as to block their view of traffic when they cross the street or be difficult for them to remove in an emergency. Masks are not recommended for children under eight, and all masks should have nose openings for easy breathing. Food parcels for children under five should not include nuts, small pieces of plastic or anything else that can cause choking.