Biting winds and freezing winter mornings are no match for a decent puffer jacket. These high-tech coats use compartmentalised ”baffles” of duck, goose or synthetic down to trap body heat and keep the cold out.
Key to this is “fill power”, a measure of the down's fluffiness and insulating ability. Put simply: the higher the number, the more warmth it traps and the cosier you'll be kept on days when the temperature drops.
