Final answer:
After confirming the fire, the nurse's priority should be to move the nonambulatory client to a safer location before alerting the fire department or addressing the fire itself.
Step-by-step explanation:
When a client who is nonambulatory informs a nurse that his trash can is on fire, after confirming the fire, the nurse's next action should be to move the client to a safer location. This is because in any emergency situation, especially one involving fire, the priority is to ensure the safety of individuals. Safety protocols often follow the 'RACE' acronym: Rescue, Alarm, Confine, and Extinguish/Evacuate, in which rescue, i.e., attending to individuals in immediate danger, comes first. Once the client is safe, the nurse can then proceed to alert the fire department or use a fire extinguisher, and take the necessary steps to contain and mitigate the fire if safe to do so. Opening windows to let smoke out is not immediately prioritized as it may contribute to the spread of the fire.