Twenty million low-birth-weight babies are born in the developing world every year. Many of them die, often from hypothermia. The Western solution–an incubator, which costs around $20,000 and requires a reliable source of electricity–is not feasible for rural hospitals.
The practical solution? Forget technology. Stanford (Jan.-Feb. 2009) reports that a group of students invented a tiny sleeping bag-like carrier that keeps babies warm in rural Nepal, no electricity (or batteries) required. It contains a removable pouch of phase-change material, which retains its temperature for four hours and is easy to reheat–parents just put the pouch under a metal container filled with hot water. And, in further consideration of the parents in question, the design is constructed of materials that are washable (vinyl and nylon) and repairable at home (buttons instead of Velcro).