Amid growing concerns over the H1N1 virus, some hospitals in Illinois have begun revising their guidelines on visitors, in some cases prohibiting children. Edward Hospital in Naperville announced that people under 18 will be prohibited from visiting the hospital unless they have a medical issue. The hospital asked others, especially people with upper respiratory problems, to refrain from visiting patients if possible. Edward's decision came two days after President Barack Obama declared swine flu a national emergency and as concerns mount over a limited supply of vaccine. Children's Memorial Hospital in Chicago also began restricting children or people with flulike symptoms from visiting patients, and restricted each patient to a maximum of two visitors.