Can sandwiches be eaten directly without heating?

Of course.

The raw materials of sandwiches include toast and sandwich foods, such as vegetables, meat and cheese. The ingredients are all cooked or processed, and can be eaten directly and safely in a cooled state. The raw materials of the sandwiches used are cooked or edible raw (such as green vegetables), and the sandwiches can be enjoyed directly. This is convenient and can maintain the nutritional value of the ingredients themselves.