1. Vacuum Insulated Bags: These use a vacuum to extract air from the bag, maintaining the temperature of food and beverages. Vacuum insulated bags generally provide excellent insulation, but are also relatively expensive.
2. Sealed Insulated Bags: These utilize the temperature difference between the vacuum inside the bag and the outside environment to create a sealed environment to maintain the temperature of food and beverages. They are suitable for shorter-term heat preservation needs and are relatively affordable.
3. Mother-and-child Insulated Bags: These bags are suitable for both heat preservation and cold preservation. They typically consist of two layers: an inner layer of insulating material and an outer layer of protective material.