How much thought do you give the hot water heater that provides you with that warm shower every morning? It is part of a complex system that relies on a century of infrastructure, water deliver, gas or electric for heating. When the grid goes down, most will long for a shower or bath in warm water.
Most will make do, but the folks with a bit of ingenuity won’t stand for it. With a few spare parts, some skill, and a little bit of sweat equity you can have an endless supply of hot water. With that being said, check out this excellent video below by Engineer775 to see how he produces hot water with a rocket stove and an old hot water heater.