Unicef is hoping that low-cost wearable tech might help solve child health problems in developing countries. The charity has partnered with British chipmaker ARM and design firm Frog to launch the ‘Wearables for Good’ challenge. It is asking designers to come up with ideas for cheap, low-power gadgets that can save lives. Unicef wants a way to monitor and measure vital signs and other biological stats, keep track of environmental conditions, and push out alerts. Devices that can track patients without being worn will also be considered.