Final answer:
Assessing nail beds is a suitable nursing intervention that can help indicate poor perfusion in a client with a fluid volume deficit, as it provides clues about blood oxygen saturation and peripheral circulation.
Step-by-step explanation:
The nurse caring for a client with a fluid volume deficit, which indicates a potential hypovolemia, should focus on interventions that address the client's potential for poor perfusion. Among the given options, assessing the client's nail beds is a relevant intervention because it provides immediate non-invasive clues about the blood's oxygen saturation and can indicate if there's adequate blood flow to the extremities. This is done through a simple blanch test. Moreover, monitoring for signs of blood loss and checking the client's temperature are also pertinent, as they can provide early warning signs of worsening hypovolemia and possible hypothermia due to poor perfusion.