Hi Thanks for posting on HCM Fever in children should always be investigated as might reveal serious conditions.In the case of your son, serious diaper rashes may cause it or a superinfected diaper rashes.The best treatment for this condition is to keep your baby s skin as clean and dry as possible.Fungal or bacteria skin infections may contribute to this condition and your Doctor may prescribe anti-fungal or antibiotic creams and steroid creams for application.I will suggest you try the following measures: -Give the child an anti-pyretic like paracetamol syrup -Keeping diaper area clean and dry and change diapers frequently to avoid being in contact with urine or stool for long -Increasing airflow by airing diaper area often -Apply Vaseline lightly while changing diapers -Bath the child daily. I will also advise you see a Pediatrician to investigate the cause of fever.He may also evaluate the rashes to judge the need for an antifungal or antibiotic cream. Hope my answer will help you Best regards