German combat rations (EPA) had a chocolate bar in them. It did not melt even when left in car in summer. That bar was one of the things that usually were left over. The taste was not really satisfying (just to be polite). Probably you donīt even need to lock it away from children. Most wont finish their first bar let alone try another one.
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If it isnīt broken, it doesnīt have enough features yet.