古代御寒“神器"——烧炭的手炉为何不会烫手？
How ancient Chinese people warmed their hands in winter

Made of bronze or ceramics, ancient hand warmers had a variety of designs. Round, square and octagonal shapes are typical, with some fashioned to look like pumpkins, flowers and turtle shells.

Inside a hand warmer, there were burning charcoal or simple coals. Some coals were blended with fragments and pressed into flower shapes, emitting a pleasant scent when burned.

There is no accurate written record regarding the origin of this tool, but there are some tales about its invention.

One folk story concerns Emperor Yangdi from the Sui Dynasty who visited Jiangsu in the winter. Due to the bitter cold, the local official asked manufacturers to make a small warmer for the emperor that could be held in one's hands. Thus the hand warmer was created.

By the Song Dynasty (960-1279), the tool was in widespread use. Techniques for producing the tool were extensively employed in the Ming and Qing dynasties (1368-1911).

Many poems and books from this period recorded people using hand warmers.

The Dream of the Red Chamber, the classic novel by Cao Xueqin from the Qing Dynasty, also featured a maid sending a hand warmer to the protagonist Lin Daiyu in one chapter.

多数手炉的通高不过18厘米，长15厘米、宽10厘米左右，看着小小的，其实里面的结构另有玄机，分为外壳和内胆两层。在精美外壳内，还有铜制的内胆。内胆多架于外壳口沿之内，方便燃炭。上面的盖子则是镂空的，便于通风换气。通过内外两层的空气传导，手炉