    At the Dursley’s, Harry was allowed five minute showers – after everybody else. Whatever hot water was left after Aunt Petunia and Uncle Vernon had their showers was used up by Dudley, meaning that Harry’s showers were more often than not cold. At Hogwarts, on the other hand, he could have a hot shower whenever he wanted. He wondered if there was a spell to heat water that he could use at the Dursley's.