The Prophets (PBUH) Medicine
As Salaamnu Alaykum
It is said in the book "The Prophets (pbuh) Medicine" to use vinegar to draw out the heat. Vinegar has natural medicinal remedies and unless the skin is broken, or blistered, this will calm it.
IF it is blistered and breaks or oozes, keep it clean and dry, and let nature take its course. Once healed put a dab of vitamin E on it, and it will take the scarring away, or reduce it.