You could be having some form of allergic reaction due to summer. Use a mild soap and cool water for bathing.
Next Steps
You can consult on private chat with clinical photographs for personalised treatment.
Health Tips
Following healthfeed should be able to help too: "15 Top Skin Problems in Summer" by Dr. Jolly Shah Kapadia - https://www.practo.com/healthfeed/15-top-skin-problems-in-summer-27648/post