The principle is to use the physical structure of pva itself to facilitate water evaporation, take away surface heat and achieve the effect of cooling.

In fact, the working principle of cold towel is the application of physics knowledge in middle school. When liquid water becomes steam, it absorbs environmental heat to achieve cooling effect. When the cold towel is thrown at high temperature, the vaporization process of water is accelerated. This is the principle of "throw it away and cool it". In view of the material characteristics of the cold towel, users can have the functions of heatstroke prevention and cooling, eye protection and skin care when going out and traveling in summer; For people who like exercise and fitness, it can bring sweat absorption, cooling, relaxation and cooling effects, and help people keep their body temperature constant and recover their physical strength during exercise. Cold towel is also an auxiliary tool for physical cooling when you have a fever, fever or scald; After sports injury, the temperature can be temporarily lowered to stop bleeding. Cold towels are very easy to use, as long as they are wetted with water at room temperature and gently twisted and tossed, they will become cold immediately.