During shelter-in-place protection, which action is NOT a protective action?

Answer: A — Ensuring HVAC system remains operating

During shelter-in-place, the goal is to limit exposure to any outside contaminant by reducing air exchange with the outdoors and staying informed through official instructions. Keeping the HVAC system running can pull in outside air or circulate any contaminants already in the space, which undermines that protective barrier. The safer approach is to minimize ventilation—turn off or set the system to recirculate if possible—to prevent outdoor air from entering and to keep indoor air within the sealed area. Monitoring local TV or radio keeps you updated with the latest instructions from authorities, so you know when it’s safe to leave or what additional steps to take. Closing all doors helps contain any contaminants to the room or area you’re in, reducing pathways for air flow between spaces. Closing all windows further minimizes the entrance of outside air and contaminants. So, the not-protective action is keeping the HVAC system operating, because it can introduce or spread contaminants indoors, counteracting the shelter-in-place protective measures.