Thin skin systems wont feel hot when you do a whole head bond. But if you attach on the perimeter and hair can get between your skin and the system, ur scalp is going to sweat and it will feel a little hot and uncomfortable. But if u cover ur scalp with got2b or glue, than there is no hair between the thin skin and ur own scalp, so u are blocking off the sweat etc.. Thats why some people claim skin systems are not hot. But if u are not the type to do a whole head bond of any form.. than u might def get hot and oily underneath the skin.