Answer :
Final answer:
Parents should contact their healthcare provider if their 3-month-old infant exhibits a temperature of 37.9 degrees C (100.2 degrees F), inconsolable crying, or vomiting as these symptoms could indicate a serious condition that requires medical attention.
Explanation:
The nurse should educate the parents of a 3-month-old infant to contact their health care provider if they observe the following clinical presentations: temperature of 37.9 degrees C (100.2 degrees F), inconsolable crying, or vomiting. An elevated temperature in an infant can be a sign of infection or other illness and requires medical attention. Inconsolable crying can be an indicator of discomfort or pain. Vomiting in an infant could signify a gastrointestinal issue or infection. These symptoms, along with difficulty feeding, irritability, and lethargy, are critical signs indicating the baby may need medical intervention. While increased activity and alertness is generally not a cause for concern, behaviors opposite to it, such as unusual lethargy, should be closely monitored and reported.