Aisoyimstan, the Cold Maker, is the Blackfoot personification of winter, who brings the cold, snow, frost and storm down from the north — a character in Grinnell's 'Cold Maker's Medicine' (Blackfeet Indian Stories, 1913). The familiar image of him as a white man with white hair in white clothes on a white horse is recorded by Lewis Spence (1914). He stands opposed to the warmth of the Sun in the turning of the seasons on the northern plains.