A thermos, also known as a thermos, is a container designed to maintain the temperature of its contents for a long time, whether hot or cold. The principle behind its effectiveness is the use of vacuum insulation, which significantly reduces heat transfer through conduction and convection. In addition, thermoses are usually made of materials such as stainless steel, which can reflect thermal radiation and further minimize heat loss. Vacuum bottles are widely used in daily life to carry hot or cold drinks and food. Here are some tips for using a thermos correctly: 1. Do not exceed the temperature limit that the thermos can withstand to avoid damaging the vacuum layer. 2. It is recommended to clean the thermos bottle with warm water instead of hot water for the first time to prevent vacuum. 3. Avoid using thermos bottles to carry acidic or alkaline beverages, as they may corrode water bottles. 4. Clean the thermos bottle with mild detergent and water; Avoid using brushes to avoid damaging the bottle. 5. The cooling effect may be affected by the ambient temperature; In high-temperature environments, the cooling effect may not be as good as the heating effect in low-temperature environments. Proper use and maintenance of thermoses can make them a very convenient and useful tool in daily life.