Firefighters often come into contact with water whether they control the fire on the periphery or enter the fire scene for rescue. The outer layer of the fire-fighting clothing will inevitably be wetted by water, and part of the moisture will be transferred to the inner layer through the surface of the clothing. At the same time, during the rescue process, firefighters themselves will produce a lot of sweat. After wearing fire-fighting clothes, the human body will sweat at a rate of 1200～1800 g/h. The sweating is to adjust the temperature of the human body and keep it within the suitable range. , To avoid overheating of the human body, however, in fire fighting operations, nearly 2/3 of the moisture will remain in the clothing layer. The heat and mass transfer of moisture in clothing is carried out through evaporation, condensation, desorption and adsorption, which is a very complicated process.
In the fire rescue process, water vaporizes into water vapor at high temperature, which is transferred to the skin surface, causing steam burns, and even human body burns without contact with the fire source. Therefore, in order to study the effect of moisture evaporation and conduction on the skin, it is necessary to understand the distribution of moisture in the fabric layer, as well as the temperature of moisture and the content of water vapor when the fabric is exposed to a heat source.
The moisture in the fabric has a great influence on the thermal protection performance of fire-fighting clothing, and also affects the thermal conductivity of the multilayer fabric. The presence of moisture increases the thermal conductivity and heat capacity of the fabric. Many scholars have studied the effect of moisture on the multilayer fabric system. It is found that under different conditions, moisture will increase or decrease the thermal protection performance of the fabric.