Soup is supposed to be drunk very hot. If you need to take it out and drink you need to put it in the thermos to keep it hot. You need to get the best thermos for soup to keep it very hot and fresh. The thermos prevents heat to escape out of the flask and hence keeps your drink or the soup hot and fresh. You just have to pour the hot soup in it and close it tightly. It uses a lot of heat transfer principles to keep the soup hot.
This basically has a bottle inside another bottle. The problem is that heat can escape through the air. The gap in between the bottles is fully filled with vacuum to avoid heat transfer. There is only a small contact that holds the bottle inside in position. The inside bottle conducts the heat in very small degrees. The heat cannot go out as it does not air outside. Radiation also takes place. The inner bottle radiates heat to the outside bottle and the outer bottle radiates heat towards the inner bottle. This is the only possibility. This is stopped by coating the surface with silver. This keeps the radiation of heat under check. That is why the best thermos for soup looks very shiny on the inner surface. Your soup will hence stay hot for a very long time. Not just soup, you can also take other hot drinks in this. It will also keep the cold drinks cold as no heat transfer takes place.
Using a thermos is very easy. It is very important to keep the thermos clean. Wash it thoroughly after every use and dry it properly. If you are using liquid other than water, make sure the thermos is moist free to keep your liquid fresh. Use a proper brush and soap to clean it. Make sure there are no particles stuck anywhere. Do not fill it to the brim. Leave some space between the liquid and the lid.
It is easy to buy a thermos. There are many sizes available in the market. You can just walk in and buy one. These are also available in many online stores. You can choose the best thermos for soup from the variety of options available. Make sure you get a properly branded thermos. These are more effective than the non-branded ones to keep your liquid hot.