A fever does not boost immunity in a small child with hand, foot and mouth disease. Hand, foot and mouth disease is a common infectious disease in children caused by enterovirus infection. Due to the low immunity of children, the morbidity rate is higher. A fever does not boost immunity in a small child with HFMD, and after treatment, there is a risk of reoccurrence if personal protection is not observed. If you want to improve your immunity, you can get inoculated with inactivated enterovirus 71 vaccine or live attenuated vaccine to strengthen your body’s resistance and reduce the risk of HFMD infection. It is also necessary to strengthen nutrition, develop good hygiene habits and avoid close contact with children suffering from HFMD, etc. to minimize the occurrence of the disease.