Can onions under your arm pits give you a fever or make ill?

No, placing onions under your armpits will not give you a fever or make you ill. There is no scientific evidence to support this claim. While some people believe that onions have antibacterial properties, there is no evidence that this is effective in treating or preventing fevers. There is also no evidence to suggest that placing onions under the armpits has any effect on the body's temperature.