Sweating is a strategy used by many animals, including humans, to cool off without expending loads of energy. So why not do the same for buildings?

Researchers at the Swiss Federal Institute of Technology in Zurich, led by Aline Rotzetter, have developed a special polymer that soaks up water in the rain and “sweats” when it gets warm. The evaporating water works to cool the house, eliminating a lot of the work of an air conditioner and saving energy in the process.