The actress portrays a young woman trapped in a spooky summer house in the horror movie, and Olsen spent much of her time on set in tears as she played out the emotional scenes.
However, all that crying made Olsen sick and by the end of the shoot, she was battling a nasty bug.
She tells Reuters, “It was (exhausting). There is so much snot in this movie because that’s what happens when I get emotional – snot comes before tears. I gave myself a sinus infection by the end of the movie. It was hard.”