Hello, Whenever a four month old baby presents with a high temperature for a couple of days with associated symptoms such as diarrhea, rashes in the groin and anal area, unresponsiveness it is a medical emergency and cannot be taken lightly. A rise in temperature does not necessarily mean it indicates meningitis. Meningitis is a condition caused by either bacteria or virus. Bacterial meningitis is usually serious and life threatening whereas viral meningitis is relatively common, less serious and known as aseptic meningitis, as its symptoms can be similar to those of the common flu. Most cases of viral meningitis resolve completely within 7-10 days without any complications or need for treatment. So depending on the symptoms and signs along with the laboratory investigations including a lumbar puncture test, your doctor can take a decision about the treatment. I would suggest you to consult your pediatrician immediately for further management. Hope this helps. Thank you.