The question title describes very succintly the object I'm looking it's name or term in English. I know the name in spanish in Argentina, it's "cuello polar", cuello means neck, polar refers to "polar fleece" a type of cloth. It's not a scarf
Note: This can be worn as a hat to cover one's head too, but it's not ideal, since it's open on both ends and the top of the head with the hole could be exposed, in comparison to a real closed winter hat.
Is worn around the neck, it's toroidal shaped, it's made of polar fleece often, it's goal it's to warm the neck but also can be used to cover mouth and nose, it's normally used in winter with low temperatures.