If, upon arrival at the emergency scene, initial attack personnel find an imminent life-threatening situation where immediate action could prevent the loss of life or serious injury, such action shall be permitted with less than four personnel.

Immediate action can be taken with less than four personnel in life-threatening emergencies to prevent loss of life or serious injury, abiding by safety definitions from NIOSH and OSHA concerning IDLH environments and moral imperatives as seen in ethical dilemmas.

Explanation:

If, upon arrival at the emergency scene, initial attack personnel find an imminent life-threatening situation where immediate action could prevent the loss of life or serious injury, such action shall be permitted with less than four personnel. This protocol is based on the understanding of various situations indicating a high level of danger, such as an atmosphere posing an immediate threat to life, likely to cause death or serious health effects, or prevent escape, as defined by NIOSH and OSHA. In the fire service and emergency response, IDLH (Immediately Dangerous to Life and Health) environments are recognized as those where immediate action is critical to save lives, despite potential risks. These decisions can be morally complex, as demonstrated by ethical dilemmas where life and death are in the balance, such as questions of risking one life to save many others, like in the trolley problem.