Even arctic temperatures are no match for this innovative and versatile footmuff. Forget about layering on garment after garment, the Sac Igloo is one of 7 A.M Enfant's most popular one-and-done solution for getting little ones all bundled up for the cold. And though it's designed especially for bitter winters, it's convertible: the removable fleece insert reveals a cotton lining that works on its own during warmer months. It fastens easily to any stroller or car seat and the detachable cover converts into a single-panel blanket.