Clothing Definitions — definitions of garments and clothing terms from Apparel Search
Long underwear usually refers to a style of two-piece underwear with long arms and long legs that is worn during cold weather. Today's long underwear, also known as long johns or thermal underwear, is worn as the base layer under clothing for work, winter sports and outdoor activity. This page explains the two-piece long john set and the older one-piece union suit, the fabrics used and how they insulate, and how to choose long underwear for different levels of cold and activity.
Most long underwear of today, also known as "long johns", is made with a box-weave, although some is also made of flannel, while others are made of two layers.
Modern long underwear is a modern innovation, largely supplanting the old union suit worn almost exclusively by men.
| The above article is licensed under the GNU Free Documentation License. From Wikipedia, the free encyclopedia (https://en.wikipedia.org/wiki/union_suit). 11/13/04 Modified by Apparel Search. |
Long underwear does not generate heat; it slows its loss. A close-fitting layer traps a thin film of warmed air against the skin, and the fabric's structure, especially the waffle or rib knits used in thermal underwear, holds more still air in its pockets. That is also why fit matters: too loose and the air layer is pumped away by movement, too tight and the knit is stretched thin. Worn under mid-layers and a shell, the base layer is the part of the system that also manages moisture, moving sweat away from the skin so it cannot chill the wearer when activity stops. Merino wool and modern synthetics do this best, which is why they dominate ski, mountaineering and workwear ranges, while cotton long johns remain a budget choice for low-activity cold.
The name long johns is often linked to the boxer John L. Sullivan, who fought in similar garments, though the connection is folklore rather than record. The union suit, the one-piece ancestor, was standard 19th-century underwear in cold climates, buttoned up the front and fitted with a rear flap for practicality. Two-piece sets displaced it because they fit better under changing outer clothes and either piece can be worn alone. Modern ranges grade sets by weight, lightweight, midweight and expedition, so a wearer can match the garment to temperature and exertion instead of owning one set for all winter.
Care is straightforward: wash synthetics and wool blends cool to protect elastic and fibres, and check waistbands and cuffs, whose recovery keeps the close fit that makes the layer work. For children and older wearers the same principles apply, with softer, non-itch fabrics preferred, and for outdoor workers a spare dry set is the standard advice, since a dry base layer restores warmth faster than adding another outer coat.
Long underwear is a style of two-piece underwear with long sleeves and long legs, worn during cold weather. It is also known as long johns or thermal underwear.
Long johns are two separate pieces, a long-sleeved top and long-legged bottoms. A union suit is the older one-piece version covering the whole body, traditionally with a buttoned placket and a rear access flap.
Long underwear is made in cotton, wool (especially merino), silk and synthetic fibres such as polyester. Wool and synthetics insulate even when damp and are preferred for active use; cotton is inexpensive but loses warmth when wet.