Final answer:
If a nurse notices a fire in the lounge, their first action should be to evacuate the area immediately.
Step-by-step explanation:
If a nurse enters a staff lounge and notices that a cushion of a chair is on fire, the nurse's first action should be to evacuate the lounge immediately. The safety of everyone in the lounge is the top priority, and it's important to remove themselves from the immediate danger and potential smoke inhalation. Once outside, the nurse should follow the hospital's established fire safety procedures, which may include calling for assistance or using the available equipment to try to extinguish the fire (if safe to do so).