A sleeveless, close-fitting or slightly loose garment typically worn over other clothing provides an additional layer of warmth for the torso in colder conditions. These garments can be made from a variety of materials, including down, fleece, wool, or synthetic fabrics. A lightweight, packable down-filled example offers excellent insulation without restricting movement, making it ideal for layering under a jacket during outdoor activities. Heavier, fleece-lined versions provide substantial warmth for casual wear in chilly weather.
Supplemental insulation for the core body area is crucial for thermoregulation in low temperatures. By trapping warm air close to the body, this type of garment helps maintain a comfortable body temperature, reducing the risk of hypothermia and improving overall comfort. Historically, similar garments have been utilized for centuries, evolving from basic undergarments to specialized outerwear designed for various activities and climates. Their continued use underscores their effectiveness in providing essential warmth and comfort.