Final answer:
The life-threatening percentage of total body volume loss is 25%, which requires urgent medical intervention to prevent serious outcomes including death.
Step-by-step explanation:
The percentage of total body volume loss deemed life-threatening is 25%. This means that when a person loses more than 25% of their total body fluid or volume, it represents a critical medical emergency that necessitates immediate medical attention to prevent severe complications or death.
For example, severe dehydration might cause such a significant loss of body fluids, and in trauma settings, such as with severe bleeding (hemorrhage), losing more than 1/4 of one's total blood volume can rapidly lead to shock, organ failure, and if not treated promptly, could be fatal.