How about hot underwear?
Heating underwear was first made in Japan, and it was only provided for mountaineers. As the name implies, heating underwear is automatic heating underwear, which has excellent cold-proof performance, but the price is also very expensive. It is a new product that has only appeared in recent years. The main raw material for making heating underwear is a special fiber material, and it is precisely because of the high price of this special fiber that the price of heating underwear remains high. When this special fiber is made into heating underwear with other fibers, it will absorb the moisture emitted by the human body and heat up. Generally, you can actively raise the temperature by 2℃ to 5℃. Wearing hot underwear in winter can really wear less clothes, but its temperature rise is limited and it can't completely replace cotton-padded clothes. There are essential differences between heating underwear and thermal underwear. Heating underwear absorbs moisture and actively heats up, and the underwear itself will heat up. Thermal underwear does not generate heat, but only reduces the heat loss of human body through its own structural characteristics to achieve the effect of keeping warm. Please pay attention to this when buying hot-selling underwear, so as not to steal the concept and deceive consumers.