Self-heating underwear only has a higher cotton content, and automatic heating is just a gimmick of merchants. According to industry standards, thermal underwear is only measured by thermal insulation rate, and products with thermal insulation rate exceeding 30% are thermal underwear. If you want to keep warm, don't listen to the propaganda of the merchants. Adding more clothes is more reliable than just wearing a "warm artifact".
Extended data:
The concept of having a fever is totally out of line with scientific common sense. In fact, heating underwear is not a "high-tech". Because any material can generate heat by absorbing water. The mechanism of fiber moisture absorption and heat generation is that when fiber absorbs water, hydrophilic groups in fiber molecules combine with water molecules, and the kinetic energy of water molecules decreases, and at the same time it is converted into heat energy and released.
Generally, the moisture absorption and heating performance is closely related to the moisture regain of fibers. Fiber has high moisture regain and poor moisture absorption and heating performance. For example, wool and modal fibers have good moisture absorption and heating effects, while ordinary acrylic fibers and polyester fibers have poor moisture absorption and heating effects.
People's Network-"Self-heating Underwear" is not reliable
People's Daily Online-Revealing the Secret of Heating Underwear: There is little difference between spontaneous heat and ordinary underwear.
People's Daily Online-A set of underwear with nearly 1,000 yuan spontaneously heats up? Expert: It's a complete bluff.