When it comes to women and mens thermal underwear, there is really no difference as far as material and purpose, and only a slight difference in style, design and usage.

Thermal undergarments are most commonly worn as a layer under clothing and outerwear such as ski jackets to keep the user warm while participating in outdoor activities during cold weather and consist of a long sleeve shirt and pants made with two layers of thin material which retain the users' body heat giving them the ability to stay warm.

The most common materials used in thermal underwear are cotton and polyester with the differences in material being that polyester can keep you drier when perspiring therefore, as most men tend to sweat more during outdoor physical activity, you will want to choose polyester over cotton when buying mens thermal underwear.

Thermal underwear is also available which is made with a special material that is dual purpose having the ability to keep the user either warm or cool which is ideal when purchasing mens thermal underwear for working outdoors where the temperature may change from cooler in the morning to warmer as the day progresses.