High fever on the 2nd day of chickenpox vaccination can be treated by physical cooling, medication and other methods. 1. Physical cooling: You can cool down the fever by wiping the forehead, armpits, palms and feet with a hot towel. You can also put a cooling patch on your forehead to lower the temperature. 2. Drugs to lower the temperature: high fever greater than 38.5 degrees Celsius not only need to carry out physical cooling, but also need to lower the temperature through drugs, common antipyretic drugs include ibuprofen or acetaminophen. After taking the medication, you need to measure the temperature several times. If the temperature rises repeatedly, you can give the medication again after 4~6 hours. 3. Hospitalization: If the above methods are not effective in improving the high fever caused by chickenpox vaccination, you need to go to the hospital in time, and the doctor will provide targeted treatment. High fever caused by chickenpox vaccination requires active intervention to avoid affecting your health.