'Dancing With the Stars' Contestant Became 'Very, Very Ill' Ahead of Motown Night

Alyson Hannigan was "very, very ill" before taking the stage for Motown Week during Tuesday's episode of Dancing With the Stars. The How I Met Your Mother actress, 43, told PEOPLE following her performance that she had a migraine that "really took [her] down" that morning and didn't think she would be able to make it through her performance with pro partner Sasha Farber.

Hannigan revealed she was "feeling much better" by the end of the night thanks to medicine, but early in the morning felt so sick she couldn't even keep fluids down. "I didn't think I would make it through today," she admitted. Farber added to the outlet that he knew something was wrong when Hannigan called him early in the morning. "As soon as I heard her voice, I was like, 'Oh, that's it.' And she was crying."

The Buffy the Vampire Slayer alum couldn't get out of bed or get to work initially, which was obviously a struggle when preparing for the night's live show. "Usually when we get to work, we run it twice and then we do a dress run," Farber explained. "She didn't run that because she couldn't walk – so she missed all that rehearsal."

Just hours before the show, Hannigan was still struggling to stand and walk, let alone dance. "I was in my trailer in the fetal position," she recalled. "It was awful. I was just like, I couldn't take 10 steps without having to throw up." After being diagnosed with a "really bad migraine," Hannigan was shocked at how it could wipe her out. "Apparently migraines, you can also be throwing up. But I didn't know that," she explained. "And I was just like, 'But I didn't have a fever. I didn't have COVID,' all this stuff. But, yeah, apparently migraines can get that serious. And now I know."

The actress would go on to score a 24 for her Foxtrot to "Ain't No Mountain High Enough" by Marvin Gaye and Tammi Terrell thanks not only to her medical treatment but also to her willpower, Farber attests. "This one is such a hard worker and she has so much, she has so much soul and power, and she worked so hard," he said. "That's why she floated tonight on a glitter canoe." Dancing with the Stars airs Tuesdays at 8 p.m. ET on ABC and Disney+.