These down jackets can be used either as a mid-layer or as outerwear when you're taking part in your usual crazy activities in colder climes. You'll barely feel a degree of cold if you're wearing a down jacket, amazing considering their lightweight designs. Windproof and water-resistant, they will keep you warm without making you too hot and uncomfortable. Elasticated sleeves will also keep out any unwanted drafts and also keep the warmth in. Despite their size, they are easy to fold away in your rucksack.