Shelter In Place

Shelter in place is to seek safety within the building one already occupies, rather than to evacuate the area or seek a community emergency shelter. The American Red Cross says the warning is issued when "chemical, biological, or radiological contaminants may be released accidentally or intentionally into the environment" and residents should "select a small, interior room, with no or few windows, taking refuge there."

https://en.wikipedia.org/wiki/Shelter_in_place