Students at MIT have developed a bracelet, called Wristify, that can change human body temperature. They say the thermoelectric bracelet could help the environment and bank balances all at once by cutting down on air conditioning and heating costs. Increasing a large building's temperature by just 1C can consume around 100 kWh a month which isn't cheap or good for the environment. The Wristify bracelet is able easily to alter an individual's temperature by several degrees. The MIT team found that altering the temperature on one part of the body can make the entire body feel warmer or colder. A change of 0.1C a second can make the entire body feel several degrees warmer or colder. The Wristify is able to work at a rate of 0.4C a second. Wristify, which is still a prototype, works using a copper-alloy-based heat sink on the wrist. It automatically measures your body temperature and makes adjustments to maintain the level that's been set. Even the prototype model is able to work for eight hours, thanks to a lithium polymer battery. “Buildings right now use an incredible amount of energy just in space heating and cooling. In fact, all together this makes up 16.5 per cent of all US primary energy consumption. We wanted to reduce that number, while maintaining individual thermal comfort,” says Sam Shames, who co-invented the Wristify with Mike Gibson, David Cohen-Tanugi, and Matt Smith. “We found the best way to do it was local heating and cooling of parts of the body.” The team came in first place in the MIT Making and Designing Materials Engineering Competition and were rewarded $10,000 which they plan to reinvest in the Wristify project.