Was at my brothers yesterday all day and Connor and my nephews were playing out in the backyard and…

Was at my brothers yesterday all day and Connor and my nephews were playing out in the backyard and playing in the kid pool. I was putting sunscreen on him all day. Well this morning I noticed he's so sunburnt. He was perfectly fine earlier but now he's in so much pain. I've been coating him with aloe vera, and gave him some Motrin. He's been screaming and crying all day. I don't know what to do.😕😭