Final answer:
The first thing a nurse aide should do when finding an unresponsive client is to call for help.
Step-by-step explanation:
The first thing a nurse aide should do when finding an unresponsive client is to call for help. This is crucial because immediate medical assistance may be required to assess and attend to the client's condition.
Placing a cold washcloth on the client's forehead may provide some comfort, but it is not the first priority when dealing with an unresponsive client.
Closing the door to provide privacy to the client and calling the client's family can be done after calling for help and ensuring the client's safety.