From early days when animal skins were the season's fashion until modern times, clothes have been typically engineered for comfort in cold environments by tailoring their thermal conduction. Air pockets in feathers, furs, and woolen fabrics help reduce thermal conduction and keep warmth inside. Cooling, however, is much harder to achieve without the use of external active devices such as fans, air conditioners, or wearable thermoelectric coolers. The wicking technology used in modern athletic apparel to enhance convective cooling is not ideal for everyday clothes because it only works once perspiration begins. On page 1019 of this issue, Hsu et al. ( 1 ) report passive cooling of an object by a few Celsius degrees by simply allowing thermal radiation to pass efficiently through a nanoporous fabric. This demonstration may make possible wearable technologies for personalized cooling and paves the way for energy savings by reduced use of air conditioning.
Boriskina, S. V. (2016). Nanoporous fabrics could keep you cool. Science, 353(6303), 986–987. https://doi.org/10.1126/science.aah5577