Bring cooling battery for shopping
When one plans to go shopping, it often happens that you take something from the freezer department, even though you did not intend to do it (eg ice hmmm: the mind was willing ...). If you have to go somewhere else, you are often at a loss to buy an iso-bag.
You can easily prevent that if you take one or two frozen batteries right from the start. If you are traveling by car, it makes absolutely no effort. If you do not need it then, not bad either - it just comes back to the freezer.
