A heavy jacket is a type of outerwear that is designed to keep the wearer warm in cold weather. The three most common types of heavy jackets are parkas, peacoats, and reefers. Parkas are typically made of waterproof material and have a hood for extra protection from the elements. Peacoats are double-breasted coats with a short length and wide lapels. Reefers are usually made of wool and have a longer length than peacoats. All three of these types of heavy jackets provide warmth and protection from the cold.