Why would we heat office buildings and make sure that the ceiling of offices maintains a perfect 73 degrees Fahrenheit while nobody is levitating? Heating and cooling offices requires a lot of energy while people are not always there. Better to heat or cool people than whole buildings seems a simple conclusion. And that’s what engineers are working on. From high-tech undergarments to fan-equipped office chairs, they are creating personal climate-control systems. We suggest that a simple sweater on cold days works wonders as well.