When is 'shelter in place' advised to occupants?

'Shelter in place' is advised to occupants primarily during situations where an outdoor hazard poses a risk to their safety, such as a hazardous material release, severe weather conditions, or any other event that may compromise their safety if they were to evacuate the building. This strategy aims to keep occupants in the building in a safe location until it is safe to leave or further instructions are provided by emergency services.

In such scenarios, evacuation could expose individuals to greater danger; thus, staying put and sealing off entry points can protect them from external threats. This is particularly relevant in high-rise buildings, where evacuation can be complicated and hazardous.

The other scenarios presented reflect situations that typically would not necessitate sheltering in place. For instance, if a fire alarm sounds, it is usually an indication for occupants to evacuate, not to shelter. Similarly, if evacuation routes are blocked, occupants would need guidance to determine the safest course of action, but the presence of danger or the urgency of the situation typically prompts sheltering rather than staying put. When there is no indication of danger, occupants would likely be advised to continue their normal activities rather than sheltering.