Wristify is a watch-like tool from MIT that can moderate body temperature, reducing dependence on air conditioners and the huge amounts of electricity they consume. From Kyle Vanhemert at Wired:

“Wristify, as they call their device, is a thermoelectric bracelet that regulates the temperature of the person wearing it by subjecting their skin to alternating pulses of hot or cold, depending on what’s needed. The prototype recently won first place at this year’s MADMEC, an annual competition put on by the school’s Materials Science and Engineering program, netting the group a $10,000 prize, which they’ll use to continue its development. It’s a promising start to a clever approach that could help alleviate a serious energy crisis. But as Sam Shames, the MIT senior who helped invent the technology, explains, the team was motivated by a more prosaic problem: keeping everyone happy in a room where no one can agree where to set the thermostat.