It is usually normal to have a lung infection without a fever, but the specifics vary from person to person. When there is a lung infection, the symptoms of fever do not necessarily occur, which is related to the type of infectious agent, the progress of the disease, and the individual’s physical condition and other factors. 1. Types of infectious agents: The pathogens that cause lung infections are many and varied, with different disease-causing abilities and substances, leading to different symptoms, and some patients don’t have a fever when they have lung infections; 2. Progress of the disease: some patients with lung infections do not have obvious fever symptoms in the early stage of the disease; some patients in the recovery period may not have fever; 3. Individual constitution: some patients who are older or in poorer health do not have fever when they have a lung infection, but their condition is often more serious and they need to consult a doctor in time.