Hot box cooking is an ancient, simple and amazingly effective way to save energy.
A hot box is essentially a slow cooker that requires no electricity, and people have been using it for centuries.
It involves removing a pot of food (e.g. stew, rice, soup, pap) from your stove, oven or other heat source, and placing it in an insulated container to complete the cooking process.
You can get commercial hotboxes (such as "The HOTBOX"), but you can also make your own. All you really need is a container like a box or a drawer, and something to wrap around the pot for insulation. You can put your pot in a snug cardboard box, then place that inside a larger box, and fill the gap between the two with insulation e.g old towels, an old duvet or sleepingbag, polystyrene foam offcuts, straw.
Then leave the pot to cook in its own heat for a several hours until the contents are done.
- Olivia Rose-Innes, EnviroHealth Editor, Health24, April 2012