Infant temperature of a high fever for three month old?

See a doctor. Fever usually means that the body is raising the temperature to stop viral or bacterial attacks. An infant retains the mother's antibodies for about 3 months. The infant's immature immune system takes over so the baby becomes more vulnerable . If the baby's temperature is very high or very low, it may be very serious go to emergency dept, hydrate, tepid not cold water for cooling, take a temperature.