“Definition: taking emergency refuge within the nearest designated safe area until notification or determination that the situation has been resolved “Extended definition: a precaution intended to keep people safe while remaining indoors where the shelter area is preferably a small interior room with no windows and may require efforts of sealing all cracks or openings with tape or other materials “Annotation: Sheltering-in-place is used when evacuating the public would cause greater risk than staying where they are, or when an evacuation cannot be performed. “Example: The preferred locations for any shelter-in-place action are interior rooms of the building that have no windows”. (DHS, Lexicon, October 19, 2007, p. 24)