when u get in the water… u get wet i know… and u slowly die (wich is weird) also u get cold that fine… and i use a fire / meat after to refill my life when im out of the water. (this helps sometime)
But when ur fully geared with weather clothing or anything. u still die… so. u lose ur stuff instant… also… looting? if you die you dont have a chance to run back to ur corpse and retrieve the goods… it will instantly disapear. and that sucks.