The shoot spanned 10 days in December, which is Antarctica's "summer." Some of the photos, including the cover, were shot from the base ship, which also carried the team from one icy land shooting site to another.
When she returned to her home in Florida, Upton said she was "very, very sick. I don't think you can go to Antarctica and stand in a bikini without that happening. But I didn't die, and I'm OK now."
Very OK, after hearing only on Friday that she was the editors' choice for the cover.
Despite the challenges of the assignment, Upton said it would likely remain her most thrilling ever, and called Antarctica "the most beautiful place I've ever been."
But for anyone else who wants to experience that magical place, she offered this bit of advice: "You are definitely recommended to keep your clothes on."