red rash and burn on neck

My boyfriend works in the sun doing block work. He has developed a really bad red, blotchy rash all up his forearm and it stops just above his elbow. It does not itch or burn at all. But he also has a problem on his neck which is very painful for him. It looks like a third degree burn and anytime he puts anything on it (lotions, creams, peroxide, etc.) it burns him. His arms look awful and his neck is in so much pain. It is brown and peeling. His arms are white on the inner arm with red blotches everywhere. If you can give me some insight I would really appreciate it. Thanks!