The growth of the baby’s body is a natural physiological phenomenon that does not trigger a fever. Most fevers are caused by viruses, bacteria, and mycoplasma, toxins that irritate the organism. The common organs infected by these toxins are the respiratory system, digestive system, nervous system and blood system. The corresponding diseases caused by the infection are bronchitis, pneumonia, enteritis, encephalitis or sepsis, septicemia, etc. Therefore, fever is only triggered when there is an infection in the body, while growth and development do not cause fever. Fever is also divided into low fever and high fever. A low fever is between 37 degrees 5 and 38 degrees 5, while a high fever is more than 38 degrees 5. A high fever is harmful to the human body and may induce febrile convulsions, which may cause respiratory and cardiac arrest. Therefore, high fever needs to be treated by applying emergency antipyretic drugs first; while low fever can be temporarily given by physical cooling.