When the temperatures are extreme it is important to dress appropriately. Thermal wear makes this easy. It typically comes as undergarments that are worn right next to the skin so they can regulate body temperature. It is very effective for keeping one warm when it is cold and cool when it is hot. It also eliminates the need to wear several layers of heavy clothes when it is cold outside.
How it works to keep the body warm
Thermal underwear is equivalent to two layers of normal clothes. This is because it is made up of two-ply fabric which enables it to trap more body heat. This added body heat insulates it against cold air and prevent heat loss. Thermal underwear is thus very effective for keeping one warm for a long time even in freezing weather.
How it works to keep the body dry
Apart from keeping the body warm or cold, thermal underwear is also made to keep the body dry. There is the type that is made with polypropylene fabric that retains more heat compared to other types. This is the ideal type for active people who work out vigorously or who work outdoors.
This type of thermal wear also has fibers that wick sweat away from the skin. In an oil lamp, the wick pulls oil from the lamp to light up and keep burning. The fibers of this type of thermal wear work the same way. Its fibers pull moisture from the body and keep the skin dry and cool. Apart from keeping the body dry and cool, it also allows the skin to breath which prevents body odor.
Types of thermal wear
Over time, the technology that is used to make thermal wear has been greatly improved. It used to be plain and simple in design and there was only thermal underwear.
Today, there are other materials that are being used to make thermal wear and there are different techniques for weaving the fabric making it possible for other articles of clothing other than underwear like shirts to be made.
Thermal wear is now made with cotton or a mix of cotton and polyester. In Europe, merino and other types of wool are also used. For union suits, which are basically full inner wear, flannel is also used. The texture of modern thermal wear is box weave which a thin inner polyester lining.