Boston (At the Boston Night Center, Toni Abraham, a nurse practitioner from the Boston Health Care for the Homeless program, supervises while nurse Jack Castro and Mark Lepore, a student from Boston University Medical School, bandage the badly infected foot of a homeless man. Often, homeless people will first present themselves to health personnel when they have serious problems with their feet. Swelling of the feet and legs, cellulitis, and skin ulcerations are common among people living on the street. Inadequate opportunities to bathe, ill-fitting and wet shoes, and exposure to the elements all contribute to medical problems. "When your feet don't work, you can’t do the things that you need to do," says one.)