A 52-yeаr-оld wоmаn wаs diagnоsed with leukemia and has been receiving chemotherapy as an outpatient. She tells the RN that she hasn't been feeling well. The patient's skin is warm to the touch and she has a low-grade fever of 100.2°F. The neutrophil blood count is less than 1000/µl (low). The nurse is concerned about the possibility of infection because of the neutropenia and low-grade fever. Explain why. Select one.