Children’s fever at night is not a cold, it may be caused by the toddler’s emergency rash, usually by itself; it may also be caused by infectious mononucleosis, which usually does not get well by itself, and needs to be actively treated with acyclovir and other medications. 1. Childhood emergency rash: Childhood emergency rash is a common pediatric rash disease, usually starting with a high fever, body temperature up to 39 degrees or more, lasts three to four days after the rash from top to bottom, and then the temperature suddenly drops. Usually the prognosis is good and no special treatment is needed. 2. Infectious mononucleosis: Usually high fever persists, body temperature can rise to 40 degrees, accompanied by obvious sore throat, generalized lymph node enlargement, some children may have hepatosplenomegaly. Usually need to take acyclovir and other antiviral treatment, at the same time symptomatic treatment. At this point, active treatment is needed, and it will not get better on its own. Children’s fever at night is not a cold for a very large number of reasons, it is recommended to consult a doctor in a timely manner, to identify the cause, if necessary, with the doctor’s treatment, the above medication need to follow the doctor’s instructions.