Daniel Radcliffe, aka Harry Potter once drank anti-freeze. He tells Conan O'Brian, he was in Canada, shooting a film and it was very cold. To stop the water from freezing in the pipes, Canadian put anit-freeze in it. Since Radcliffe was unaware of this fact, he drank a full cup of water/anti-freeze. 'I got horrendously ill and didn't know why I'd become so sick. A couple of weeks later I went to drink another glass while in hair and makeup and they were like 'what are you doing.''