Skull caps are close-fitting, brimless caps that cover the entire head from the forehead, to the ears, to just above the back of the neck. Skull caps are designed to insulate the head against the cold and can be found on a wide variety of designs, colors, and fabrics.
Winter is the coldest period of the four seasons. Winter occurs between fall and spring; during the months of December, January, and February in the northern hemisphere; and during June, July and August in the Southern hemisphere. Winter is characterized by cold weather, with snow and ice on the higher latitudes.