Final answer:
The nurse should apply a warm blanket to increase the client's body temperature after a cholecystectomy.
Step-by-step explanation:
The first nursing action that is appropriate when a client has a temperature of 94.8 degrees Fahrenheit after a cholecystectomy is to apply a warm blanket and check the temperature in 10 minutes. This low body temperature is known as hypothermia and can occur due to various factors, such as exposure to cold in the operating room or during transportation from the Post-Anesthesia Care Unit (PACU) to the surgical unit. Applying a warm blanket helps to increase the client's body temperature gradually.