How to control body heat. Always get mouth ulcer over my tongue and difficult to pass faeces. Burning sensation. Excess body heat. Note: I work with system more than 10 hours a day. Also had some stress issues in work. Key note: I had unprotected oral sex a month ago. And previously some times a long ago. By any chance that might be the reason? Also, i've been tested negative for syphilis - vdrl test in april. I have no other symptoms.