Swiss architect Fabien Roy has designed an incubator for hospitals in sub-Saharan Africa that may save some of the 1.1 million premature babies lost to hypothermia each year due to power cuts. The Robust Nest incubator can keep babies warm for up to four hours. When the incubator is plugged in, the energy heats pouches of paraffin wax inside the battery, turning the wax into liquid. During a power cut, the paraffin solidifies and releases energy as heat which keeps the baby warm. The incubator's thermal battery can last through one million cycles of heating and cooling.