If your 9-month-old baby has prickly heat, you need to go to the hospital in time and use medication under the doctor’s guidance. You can use topical medication such as glycerite lotion and prickly heat powder to treat the problem and keep your body dry and breathable. The scientific name of prickly heat is corn rash, which is caused by the blockage of the sweat ducts of infants, and high indoor temperature and humidity, and the baby’s clothing is not breathable, there are four types of prickly heat: white prickly heat, red prickly heat, pus prickly heat, and deep prickly heat. White prickly heat is more common in 9-month-old babies, and can be treated with topical medications such as glycerite lotion and prickly heat powder. Red prickly heat can be treated with topical glucocorticoids and other creams, such as hydrocortisone butyrate cream and dieldrin cream. Pus prickly heat can be added with antibiotic medication such as erythromycin ointment and mupirocin ointment. Pay attention to the daily care of your child after prickly heat, and avoid sweating a lot. Wear loose, breathable clothing and a thin blanket in summer. When the weather is hot, open the windows and use air-conditioning to cool down the temperature. You can also apply prickly heat powder on areas that are prone to prickly heat, such as the neck and armpits.