Final answer:
The nurse should administer oxygen before notifying the health care provider to improve oxygenation and reduce the workload on the heart.
Step-by-step explanation:
The nurse should administer oxygen before notifying the health care provider. Increased pulmonary congestion, increased heart rate, and cold, clammy skin are all signs of worsening heart failure. Administering oxygen can help improve oxygenation and reduce the workload on the heart.