In which phase does the provider address life-threatening injuries while under fire?

The correct answer is Care Under Fire. This phase is specifically focused on providing care to the casualty while under hostile fire, which presents unique challenges and risks. During this phase, the provider prioritizes their own safety as well as the safety of the casualty, ensuring that life-threatening injuries are addressed promptly while also considering the tactical situation. The care provided during this time may be limited due to the necessity to maintain cover and return fire if needed.

In contrast, Tactical Field Care occurs after the initial enemy threat has been mitigated, allowing for a more thorough assessment and treatment of injuries without the immediate danger of enemy fire. Tactical Evacuation Care is provided once a casualty is being evacuated from the site to a higher level of care, and Casualty Extraction refers to the process of retrieving a casualty from a dangerous area, which may include elements of both care and movement but does not emphasize providing care while under direct threat. Each of these other phases focuses on different aspects of care and safety management in combat situations.