This weekend Sienna Miller enjoyed the heatwave in a classic British summertime outfit—until you take a look down at her feet, that is. She wore a blue and white striped T-shirt with cropped kick flares, a yellow tote bag by Frame and a pair of Wayfarers, but then she wore a very un–Sienna Miller pair of sandals: a pair of red fluffy flat sandals with two straps and a chunky buckle. These fluffy sandals might be a little out-there, but furry sliders are having a moment as the likes of UGG and Prada have furry sandals on sale right now. Keep scrolling to see (and shop) Sienna Miller's heatwave outfit.