Roseola in infants is an acute febrile infectious disease caused by human herpesvirus type 6 or type 7. During the acute phase, this disease often presents with a sudden high fever, with temperatures reaching up to 39°C (102.2°F), and even exceeding 40°C (104°F). The fever usually lasts for 3-5 days. During this time, it is important to monitor the baby's temperature closely. If a high fever occurs, timely antipyretic treatment should be administered to prevent potential high fever convulsions. Attention should also be given to the baby's mental response; if the baby appears lethargic and the fever persists, symptomatic treatment should be provided promptly. It is also crucial to be vigilant for any potential complications. Most children with roseola will develop a rash after 3-5 days of fever, which lasts about two days. If there are no complications, they can generally recover. Therefore, there is no need to be overly anxious if a child contracts roseola, as it is a self-limiting disease that typically resolves within 5-7 days.