 [ Symptoms ] what if i lose my medicare do i get a plan that pays the 20 that is left [ Disease ] according to the american academy of pediatrics call your doctor if your baby is under 2 4 months old and has a fever is lethargic and not responsive to you has problems breathing or eating has a rash shows signs of dehydration such as fewer wet diapers dry mouth no tears with crying or sunken soft spot on the head has a seizure it can be difficult for doctors to tell whether a newborn has a simple virus like a cold or a more serious infection like pneumonia or meningitis that is why doctors will sometimes order special tests such as blood or urine tests or a spinal tap to pinpoint the exact cause of an infant fever and to look for more serious infections in young babies