First of all, the body temperature rises when you have a fever, and the metabolic rate of the body increases due to the increase in body temperature, which results in a greater consumption of energy and oxygen for the body, so you will feel fatigued and have the symptoms of wanting to sleep. In this case, the body can recover its energy after 2-3 days of antipyretic treatment. When reducing fever, it is necessary to choose the appropriate medication according to the body temperature. When the body temperature is high, it is recommended to use ibuprofen suspension or acetaminophen suspension for fever reduction treatment. If the body temperature is not too high, the effect is often good by using Chinese medicine, such as antelope horn granules or cold and fever granules. If intracranial lesions occur, they may also lead to fever and sleepiness, such as viral encephalitis, which requires a CT head examination to rule out organic head lesions, and an EEG to rule out functional lesions.