LOS ANGELES, Nov. 7 (UPI) -- Daniel Radcliffe accidentally drank antifreeze on the set of Horns.
The 25-year-old actor related the story Thursday on Conan. Horns filmed in various locations in British Columbia, Canada, and Radcliffe told host Conan O'Brien he was unaware the water on set had been treated with antifreeze.
"It is very cold in Canada, and as a solution to that, because they don't want the water to freeze in the pipes and the trailers overnight, they put antifreeze in it. It's all non-potable water comes out of the tap," he explained.
"I did not know that!" he related. "So I, like, drank a full cup of non-potable water. So, I guess, like half antifreeze, or whatever it would've been ... I got just horrendously ill and didn't know why I had become so ill."
Radcliffe drank the toxic water alone in his trailer, and was stopped by hair and makeup artists when he attempted to drink another glass a couple weeks later. The actor said the poison made him "real sick" and gave him a "drippy tummy," and advised the audience, "Don't drink antifreeze!"
Horns is based on Joe Hill's 2010 novel of the same name, and stars Radcliffe as Ig Perrish, a young man accused of the rape and murder of his girlfriend Merrin (Juno Temple). The character grows horns that compel others to spill their secrets, and he uses the ability to track down the real killer.
Horns opened in theaters October 31, and Radcliffe is scheduled for Trainwreck, Frankenstein and Brooklyn Bridge in 2015.