My 7 month old is running a 100.9 fever should i take him to the doc?

Maybe: Infants greater than 2 months that have a temperature of 101 deg. F should be kept well hydrated with breast milk, formula or oral rehydration fluids (like pedialyte) and given tylenol (acetaminophen) in the does of 15mg/kg every 4hours. If your child is not feeling better in 24 hrs, they should be evaluated by a medical provider. If your child shows signs of worsening illness, seek help faster!