Chickenpox can be mild or severe, and most of the severe cases can have a significant fever, while some of the mild cases can have no fever. In adults or adolescents with chickenpox, the symptoms are usually slightly more severe and fever is very common, and the fever usually starts a day or two before the rash appears. If an infant or child develops chickenpox, the corresponding symptoms are less severe than in adolescents or adults, and it is likely that fever will also occur, but the fever is usually on the day the rash appears, or some children do not develop fever at all, so the absence of fever indicates that the overall condition of chickenpox is less severe. However, whether the chickenpox is indeed milder should depend on whether the rash of chickenpox is relatively small and on whether the chickenpox is without complications such as chickenpox hepatitis and encephalitis.