Sydney Sweeney says her body 'began shutting down' because of her 'Madame Web' wig: 'I was overheating'

• Sydney Sweeney told Cosmopolitan UK she overheated and vomited on the set of "Madame Web."
• The actor wore a strawberry blonde wig to play Julia Cornwell in the Sony Spider-Man Universe film.

"Madame Web" star Sydney Sweeney has opened up about one of the worst days she experienced while shooting the superhero film, which critics have derided.

Sweeney plays Julia Cornwall in the Sony Spider-Man Universe film, which focuses on a New York-based paramedic named Cassandra Webb (Dakota Johnson), who develops the power of clairvoyance. Cassie uses the ability to try to save three teen girls, including Sweeney's character, from a villain named Ezekiel Sims (Tahar Rahim).

Sweeney chose to wear a strawberry blonde wig for her role in the film instead of dying her naturally light blonde locks, which ended up temporarily pausing production and causing a small health scare.

In a video interview with costars Isabela Merced and Celeste O'Connor for Cosmopolitan UK, Sweeney stated that she took the longest to get ready on set because of the wig.

"I had a wig, so it was a whole other process. You have to wrap the wig, then glue the wig down, then style the wig," Sweeney said, before revealing the additional downside of wearing a hairpiece she soon discovered.

"And that wig was so hot we were filming in Boston in the middle of the summer," she continued.

"It was one of the hottest days, and we were in the middle of filming, and I go, 'One second,' and I turn around, and I just started throwing up, and then I turn back, and I go, 'We're all good. We can keep going.'"

She clarified that she didn't believe she was experiencing heat stroke but added: "I was overheating. My body was shutting down."

Her costars commended Sweeney for her professionalism but said despite the "Anyone But You" star's insistence she was fine, filming was stopped temporarily to check on her.

"We were like, 'No, we're not just going to roll right now, but you were ready to rock 'n' roll," O'Connor said.

"Somehow, she made throwing up professional," Merced added.