There are a wide variety of insulated lunch boxes on the market, and there are many types, and attentive parents will certainly not be negligent on this issue. So the question that comes with it is, how to choose the right insulated lunch box?

The thermos was the most fashionable household item in the 1960s, 70s, and 80s. At that time, the thermos was very precious. Parents used it as a dowry for their daughters to marry. If used properly, a thermos will be used for many years.

When people are close to the fire source, they will feel warm. This is the heat from the fire source. This is the heat radiation. The best way to prevent the heat radiation is to reflect it back with a mirror.

For office workers, they need to bring an insulated lunch box every morning to solve the lunch problem at noon. So, do you know how long the insulated lunch box can keep warm?

The thermos bottle can not only keep heat, but also keep cold things at lower temperature. When a popsicle is put in, it can also isolate the hot air from outside from entering the bottle, and the hot and cold air cannot be convective to achieve the effect of keeping cold.

Usually the food we put in the insulated lunch box is hot. At this time, the air in the insulated lunch box will be heated and expanded. When we close the lid and seal the insulated lunch box and leave the insulated lunch box for a period of time, the food and air in the insulated lunch box will coo......