Must Watch!!! Kate Upton Hot & Sexy Photo Shoot

Kate Upton's Sports Illustrated Swimsuit Issue cover is very hot -- but during her photo shoot in Antarctica, all the model could think about was the freezing cold. "It was definitely the hardest shoot I've ever done," Upton, 20, tells PEOPLE. "The best as well -- Antarctica is one of the most beautiful place I've ever been to. But I'm from Florida, so it was pretty painful." Get more stories on your favorite celebrities by subscribing now. The pain paid off, however: the perfect shot earned Upton her second consecutive SI cover, a distinction not seen since Tyra Banks covered back-to-back issues in 1996 and 1997. "Everything about the picture is perfect," Swimsuit Issue editor MJ Day tells PEOPLE. "The light, the background, the suit. It's different from what we've done in past years, and it was an exciting moment for us to have those photos work out." RELATED: See more Swimsuit photo shoots on SI.com! Exciting, because Day and her crew didn't know if they'd get any usable photos out of their Antarctica shoot -- the first-ever fashion shoot on the continent. "It was difficult," Day admits. "First of all, it's cold, even though we were there in summer. The windchill was sub-zero -- the elements are really working against you." As the crew dealt with a whole host of issues -- batteries dying in the cold, crazy weather rolling in and out -- Upton was a total pro, Day says. "She never complained. She'd just say, 'Okay, let's go do it again.'" Because of costs and the planning required to go to Antarctica -- Day says this shoot was three years in the making -- Upton was the only model taken to the faraway locale. "I knew that if I needed to bury someone in clothing, I needed her physique and curves to come through," Day explains. "So to bring her was obvious: I knew I could put a one-piece on her and she wouldn't look flat, she'd still look voluptuous and healthy and shapely and sexy." Upton's now-infamous Canada Goose Chilliwack Bomber coat, paired with white Letarte by Lisa Cabrinha bottoms, was an afterthought. "I figured, why not a coat?" Day says. "We threw it on, took maybe 100 frames, then moved on. Then that night, the photographer and I were looking at photos, and he said, 'I don't know, could this be it?' It just had that energy." Kate Upton Swimsuit Photos - Sports Illustrated Swimsuit 2013 Photos: Kate Upton is Sports Illustrated Swimsuit cover girl again Kate Upton 2013 Sports Illustrated Swimsuit Bodypaint Video: Kate Upton's Sports Illustrated Swimsuit 2013 Russian model imitates Kate Upton's Sports Illustrated Kate Bock Is Sports Illustrated Rookie Of The Year 2013 Kate Upton Bikini White Antarctic Hotness in Sports Illustrated Kate Upton's Boobs Rock the 2013 Sports Illustrated Swimsuit Issue