Although all people exposed to hazardous materials at a WMD site should ideally be decontaminated at a station in the field, a 2004 study on mass-casualty incidents that occurred between 1993 and 2000 found that one-third of those exposed to hazardous materials were not decontaminated in the field. In the aftermath of the 1995 Tokyo subway sarin attack, for example, 80 percent of the victims referred themselves to hospitals without being decontaminated in the field. In effect, these individuals became mobile "warm zones," i.e., they exposed others to some level of contamination. Exposures for hospital staff that treat such individuals usually result from proximity to or contact with a patient whose clothing or skin is contaminated. Hospital medical personnel who may treat these individuals currently lack the PPE needed for such work as well as training in how and when to use existing PPE. In addition, many healthcare providers are uncomfortable wearing current hot, cumbersome, confining PPE that restricts tactile sensations and inhibits communication with patients and other staff members. There is a critical need to improve PPE technology. This article describes some of the new technologies being developed for PPE, including nanotechnology (the manipulation of material at the microscopic level).