It has been very hot and humid lately and I developed a rash under my breast (which are large), so I thought it to be a heat rash. I have been doing a lot of work causing sweat to just pour off of me, therefore making it hard to keep a dry bra on. Then it got so bad that it hurt to wear a bra. I was told to put some baby powder with cornstarch on it to help keep it dry. I have been applying that for the last 3 days, several times a day with no improvement. In fact, it's gotten worse. It now resembles a yeast infection of the skin. Did the baby powder do that, or just the heat/sweating? Would it be ok to put yeast infection medicine on it?