How to reduce a child's fever of 39°C as quickly as possible
Sep 11, 2025
Source: Cainiu Health
Dr. Zhou Xiaofeng
Introduction
A child's fever of 39°C may be caused by post-vaccination reactions, high environmental temperature, upper respiratory tract infection, infantile emergency rash, bacterial tonsillitis, or other reasons. It is recommended to seek timely medical attention, identify the underlying cause, and then rapidly reduce the fever through physical cooling methods, medication, or other treatments under a doctor's guidance. Additionally, the child's body temperature should be closely monitored daily, with measurements taken every 1–2 hours.
Generally, a child's fever of 39°C may be caused by post-vaccination reactions, high environmental temperature, upper respiratory tract infection, infantile emergency rash, bacterial tonsillitis, and other reasons. It is recommended to seek timely medical attention, identify the cause, and rapidly reduce the fever through physical cooling methods and medication under a doctor's guidance. Detailed analysis is as follows:
1. Post-vaccination reaction: After vaccination, the body produces an immune response, which may cause transient fever reaching 39°C, usually appearing within 24-48 hours after vaccination. Promptly loosen the child's clothing, keep the room well-ventilated, use warm water to wipe the forehead, armpits, and groin areas for physical cooling; encourage the child to drink more warm water to promote metabolism, and the fever typically subsides on its own within 1-2 days.
2. High environmental temperature: Stuffy indoor conditions or excessive clothing can hinder heat dissipation in children, leading to a fever of 39°C. Immediately lower the room temperature to 24-26°C, reduce the child's clothing, and use a fan to assist ventilation; avoid tightly wrapping the child, expose their skin to facilitate heat dissipation, and combine with warm sponge baths to rapidly lower body temperature.
3. Upper respiratory tract infection: Viral infection causes inflammation, which stimulates the body's temperature center, resulting in a fever of 39°C. Under medical guidance, administer medications such as acetaminophen suspension drops, ibuprofen suspension, or pediatric Chai Gui antipyretic granules to rapidly reduce the fever.
4. Infantile emergency rash: A viral infection causes sudden high fever up to 39°C in children, followed by a rash after 3-5 days. During the fever phase, follow medical advice to use acetaminophen or ibuprofen preparations to reduce fever and prevent febrile seizures; after the rash appears, maintain skin cleanliness, avoid scratching, and typically the rash fades within 1-2 days without special treatment.
5. Bacterial tonsillitis: Bacterial infection of the tonsils leads to purulent inflammation, causing fever of 39°C accompanied by sore throat. Follow medical advice to use pediatric amoxicillin granules, cefaclor dry suspension, azithromycin dry suspension, and other antibacterial medications to control the infection.
In daily care, closely monitor the child's temperature changes, measuring every 1-2 hours; ensure adequate sleep and provide a light diet during fever, avoiding oily and spicy foods.
