keeps on one's toes (verb) beware: be careful
Sinonime: algific, antarctic, arctic, biting,
bitter, chill, chilled to the bone, chilling, chilly,
cold, freezing, frigid, frigorific, frost-bound, frosty, frozen over, gelid, glacial, glaring, iced, polar,
raw, refrigerated, rimy, shivering, shivery, sleeted, smooth as glass
Antonime: unfrozen,
watery