Final answer:
In the Care under fire phase, the only medical treatment done is providing immediate lifesaving measures to prevent further injury or death, such as hemorrhage control and airway management.
Step-by-step explanation:
In the Care under fire phase, the only medical treatment that is done is providing immediate lifesaving measures to prevent further injury or death. This includes hemorrhage control by applying pressure to stop bleeding and airway management to ensure the patient can breathe. However, full medical treatment is not possible during this phase due to the ongoing threat of danger.