A runny nose, cold, and mild fever are most often due to a viral infection like the common cold or early Influenza, and these usually improve within a few days with simple care such as adequate rest, drinking plenty of warm fluids, and eating light, nutritious food. You can take paracetamol for fever and body aches, use steam inhalation to relieve congestion, and saline nasal drops for a blocked or runny nose; antihistamines may help reduce sneezing and nasal discharge if needed. Antibiotics are generally not required unless a doctor confirms a bacterial infection. Avoid cold drinks, dust, and smoke, and maintain good hygiene to prevent spreading the infection. If symptoms persist beyond 4-5 days, worsen, or you develop high fever, breathlessness, or chest pain, you should consult a doctor for proper evaluation.