What term describes positive pressure ventilation supplied to a subject's face within a confined space?

The term that describes positive pressure ventilation supplied to a subject's face within a confined space is "Microatmosphere." In the context of confined space rescue, microatmosphere refers to a localized environment that can be modified to enhance conditions for a victim, usually by supplying fresh air directly to them. This method is crucial when a victim is in a space where the ambient air is compromised due to contamination, lack of oxygen, or other hazardous conditions. By creating a microatmosphere around the victim with positive pressure ventilation, rescuers can effectively support respiratory needs and potentially stabilize the subject until they can be safely extracted.

This targeted approach helps to safeguard the victim's immediate respiratory health, making it a critical component of confined space rescue operations.