Although the box lunch insulation bag can keep warm, the effect is average and the time is not long. How long can the lunch bag be kept warm is a question for many people now. After all, many people bring their own food at home in order to eat more nutritious food, so we know that the heat preservation time of lunch bags is usually within 1-4 hours. But it has something to do with the weather and temperature.

2. How to clean the packaging of the insulated lunch box: wash it with hot water.