There are more than one ways in which we lose our body heat. These include convection, conduction as well as evaporative cooling. Conduction is the process which takes place when the body heat gets transferred to a cool solid object from a warmer object. This would be experienced by anyone who has ever sat on metal benches in winters. Convection is when your body heat gets transferred to gas or a liquid. This often happens when the weather is windy or you’re in a pool during the summers. Evaporative cooling takes place when a liquid which is changing into gas derives energy in the form of heat from the surroundings. Let’s find out how thermals help in keeping the body warm:
What do Thermals do?
The main job of thermal underwear is to fight off evaporative cooling. The structure and fabric of thermals are such that they function as convection heat loss fighter or, to put it simply, as insulators. Thermals for women and men keep the air which is close to our skin in the right place. This makes sure that when the body is warmed up, the cool winds don’t get to blow away the warm air on your body. It also slows down the leakage of air into the cooler outside. It works on similar principles as that of the double glazed windows.
The insulating space of air that the thermals create can be described in a single word, that is, ‘loft’. The thermal inner wear is capable of trapping plenty of air which keeps you warm and they have a very high loft.
How do the Super Thin Thermals Work?
As mentioned earlier, the thermals are designed in a way to primarily fight away evaporative cooling. They do, however, give our bodies insulation. To understand it better, here is a simple example: Blow on the back of your hand and then lick it. Blow again. The wet would feel a lot cooler. This is because, while evaporating, the water derives energy in heat form away from the skin. Similarly, thermals draw or ‘wick’ perspiration away from your skin. This further minimises evaporative cooling.
Wool, fabric blends like wool and bamboos as well as synthetic fibers such as acrylics possess brilliant wicking properties which help in keeping you warm and dry even when you are out and exposed to the cold climate. Wool is revered for absorbing over 30 per cent of its actual weight in water before the fabric starts feeling wet.
How Tight should the Thermal Be?
For ensuring maximum effect, the base layers or inner wear should be well fitted, neither loose nor tight. It is more likely for the cold to get in if you have gaps/spaces between your skin and the thermal fabric. The best way to find the right fit for you is by going by your actual size as the thermals are usually made a little smaller in size than the normal t-shirts. Therefore, be it thermals for women or men, you don’t need to go a size up or down to get the perfect fit.