Worn over a long shirt, these padded vests are great for keeping your upper body warm. Another great advantage of a sleeveless jacket is that it won't constrict your arms; if you wear one while climbing, paddling or even trail running, you'll enjoy full freedom of movement. Synthetic fibre waistcoats in particular are an ideal choice for these sports, as they're robust and breathable, keep the body warm even when wet and dry quickly. Outdoor waistcoats often have a higher collar to protect the neck from the cold. A synthetic fibre waistcoat should have several pockets for your keys, mobile phone, energy bars or whatever small items you need for your activity.