The Fighter star has been in a run of musical Into the Woods at the Delacorte Theatre since the beginning of the month. It is due to end on Saturday (September 1).
She recently admitted on The Late Show that the outdoor setting of the play has presented her and her fellow cast members with some challenges.
Adams told David Letterman: "I was singing a song in some lightning the other day. That made me a little nervous."
As well as the adverse weather conditions, the 38-year-old mother also said that New York has been experiencing one of its hottest summers in history.
She explained: "I've learned a whole new level of sweat that I never thought I would achieve. It's like I'm in a steam room every night. I try to treat it like the spa."
The star of Disney's Enchanted film also joked that some small animals even made their way onto the stage and that people teased her because of her role as the princess in the 2007 film.
Adams added: "They surprised me, once I was reaching for a prop, and there I was face-to-face [with a raccoon].
"We did have people think that it was part of the show at one point, but it's not."