What is a thermal base layer?
A thermal base layer is a thin layer of clothing that insulates your body in cold and freezing conditions. It’s usually worn underneath other items of clothing. Layering is a good way to trap air and maintain body warmth, with the option to remove it if it gets warm.
When it comes to thermal base layers, there are three different kinds of fabrics; each has its advantages. Lightweight thermals are worn in moderate or cool temperatures, midweight thermals for cold temperatures and heavyweight thermals when the weather is freezing.
Through research and development, The North Face® has concluded the best thermal base layers are made of materials such as synthetic fabric that is a blend of polyester, spandex, nylon, and lycra that provides just the right amount of warmth with heat retention and moisture-wicking properties.
Wool might get itchy, silk might not be warm enough and cotton can make you feel uncomfortable with its moisture retention.
A thermal should support your day-to-day activities like travelling, going to the gym, yoga and other adventure sports.
Thermal base layers should be made of fabric that is stretchy, moisture-wicking, moisture-managing as well as warm. It should be soft and comfortable to wear as it is going to be your first layer of clothing next to the skin. A good thermal base layer should provide all-around comfort and protection during colder months.