 [ Symptoms ] can you use vicks vapor rub on a 4 month old [ Disease ] can you yes should you probably not but that would be up to your child is pediatrician there have been some studies that have shown a worsening of symptoms when vicks is used it is not very effective in controlling any of these cold symptoms so you really do not need to subject your baby to this either rubbed on there chests some grandmas even feel that putting on the feet will help  or in a hot vaporizer i know that many of us were raised by a parent that used vicks and we survived but that does not mean it is 100 safe in infants in my pediatric practice i discourage the use of vicks on a baby this young and ignore the dirty looks that i get from the grandmas when i inform them for adults and older kids they can use it if they want