Final answer:
The nursing assistant should wait at least fifteen minutes before retaking the temperature.
Step-by-step explanation:
The appropriate action in this scenario is for the nursing assistant to wait at least fifteen minutes before retaking the temperature. This is because the client has just taken a sip of hot tea which could artificially raise their body temperature. Waiting for fifteen minutes allows the temperature to return to its normal level before retaking it.
Keywords: nursing assistant, temperature, elderly client, hot tea, wait, fifteen minutes