For those of us living in the developed world, the simple act of cooking doesn't require much: You turn on the stove, and leave it on for as long as it takes to cook whatever you're preparing.But for those in developing nations, simply leaving a pot of anything on the boil can lead to disasters both ecological and humanitarian.

In developing countries, the basic need to feed a family has huge challenges: Staple diets require long cooking times, yet there is little access to energy and water. Lack of clean fuel means using charcoal or tree-wood for cooking. Cooking over a charcoal or wood fire means smoke inhalation. Little income to afford charcoal means cutting down trees. ...

To solve this problem, South-Africa-based entrepreneur Sarah Collins and social activist Moshy Mathe came up with the Wonderbag. By filling a polycotton bag with recycled polystyrene beads, the duo have created an object that can be safely draped around a pot that has just been brought to boil. The Wonderbag then keeps the pot and its contents hot for hours, without the original heating source