Final answer:
The nurse should assess the client's ability to swallow before giving fluids to a client who just returned from surgery and is asking for fluids due to thirst.
Step-by-step explanation:
Before giving fluids to a client who just returned from surgery and is asking for fluids due to thirst, the nurse should assess the client's ability to swallow. This is important because if the client is unable to swallow, there may be a risk of aspiration or choking. The nurse can assess the client's ability to swallow by observing their facial expressions, listening for any coughing or choking sounds, and asking the client if they have any difficulty swallowing.