Kate Upton made history by landing on the cover of the 2013 Sports Illustrated Swimsuit Issue - making her the first model to land back-to-back covers since Tyra Banks in 1996 and 1997 - by the model said the project was not easy.

"It was definitely the hardest shoot I've ever done," Upton, 20, told People. "The best as well - Antarctica is one of the most beautiful places I've ever been to. But I'm from Florida, so it was pretty painful."

Upton only found out that she landed the magazine's cover after the shoot was over. She told the magazine at that point she was already happy to be featured in the magazine and that "it was an accomplisment just to get through the shoot."

"I didn't even think about the possibility of being the cover until after I thawed out a bit!" she said. "But now it's like, wow - I actually went down there and was able to accomplish that. I'm part of history, and it's a great feeling (sic)." 

Further discussing the photo shoot on the Today show Tuesday, the same day the SI Swimsuit Issue hit newsstands, Upton said she was "very surprised" upon finding out that the shoot was going to take place in Antarctica. She joked on Twitter when she returned from the trip that it took her two months to thaw out her frostbite.

"When I came back I was losing hearing and eyesight because my body was shutting down," she said. "It was working so hard to keep me warm. My mom's in my ear going 'I told you not to go there. It's a bad idea!'"

Upton told My Fox Detroit, reported on Thursday, that she is currenlty single. Her comments on Valentine's Day put to rest her long-rumored relationship with Detroit Tigers ace Justin Verlander. The two met in 2012 on the set of a MLB video game commercial and the New York Post reported that they were spotted celebrating New Year's together on St. Thomas.

"Actually, I'm single right now," she told the news station's Jason Carr when asked about her reported island vacation with Verlander, 29. "So, um, I spent my holiday in Melbourne, Florida."