Suggest Treatment For Pain And Brown Layer On Top Of The Nipples

Hello, I m a little concerned about my breasts, I m young, never been pregnant. I went to the beach yesterday, and it was a normal day, water cold as always, but after 20 minutes spent in the water, my nipples felt like they were frozen, and after ignoring the constant pain, we finished with the water. one of my friends and I headed for the jacuzzi back home, and it felt good not to be cold anymore, although after having a shower, I noticed it still badly hurts when touched even the slightest, and it has formed a brown layer on top of both nipples, looking as if it were burned, is something wrong or would it go away eventually?