Refrigeration.
It is essential for storage of some foods. Electricity may be a problem. Luckily there are refrigerators that can operate without electricity. One such type is Einstein or absorption refrigerator.


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They are usually used in RV's or mobile refrigerators (like some used by salesmen). It can operate from a source of heat. They are fitted with gas, kerosene or even electrical heat source and can be retrofitted with any other small flame source that is available.