How is it that I get hot water immediately in my hotel room?

After a grueling red eye from Sacramento to Boston (w/ s.o. in Chicago) I couldn’t wait to take a hot shower. I noticed that the water was hot as soon as I turned it on. At home I have to let it heat up for a couple of minutes. Also, I’m on the fifth floor yet I am getting very strong pressure as well, much better than at home. I then realized this is usually how it is in whatever hotel that I happen to stay. So how do they do that?