| | Conditions & Treatments | Infectious Diseases Is 97.3 a high fever for an 18month old? A high fever for an 18-month-old is considered to be anything over 102.2 °F (39 °C). A child of this age with a fever of 97.3 °F (36.3 °C) does not have a high fever. Infectious Diseases - Related Articles How do spread malaria? Group B Strep Symptoms Do you run a fever with staph infection? Can eliminating infectious agent interrupt the transmission of disease? Can you give flu vaccine and pneumococcal together? Rose Spots and Typhoid Fever What Is Ciclopirox Cream Used For?