古代御寒“神器"——烧炭的手炉为何不会烫手？

在没有暖气、没有电热毯、没有暖宝宝的时代，聪慧的古人发明了火墙、炭盆等取暖“神器”过冬御寒。此外，古人日常应用较广、较常见的还有一种叫做手炉（hand warmer）的取暖器物。

手炉是古人常用的冬日取暖之物，多为铜制，也有银、铁、瓷制，里面放置火炭或尚有余热的灶灰，可以捧在手上，小型的可笼进袖内，所以又名“袖炉”。

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.
古代的手炉多由青铜或陶瓷制成，设计多样，主要样式有方、圆和八角形，还有一些手炉形似南瓜、花朵和龟壳。

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.
手炉内放置着燃烧着的木炭或煤块。有些煤饼中混合了香料，压制成花朵形状，燃烧时散发出宜人的香气。

There is no accurate written record regarding the origin of this tool, but there are some tales about its invention.
关于手炉的起源没有明确的书面记载，但民间流传着一些故事。

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.
传闻隋炀帝下江南时，由于冬季天气严寒，当地官员要求店家为隋炀帝制作一个可以拿在手里的小暖炉。于是手炉就此诞生。

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).
到了宋代（960年-1279年），手炉取暖已经流行开来。明清时期（1368-1911）手炉的制作技艺得到广泛普及。

Many poems and books from this period recorded people using hand warmers.
这一时期的许多诗歌书籍都记载了人们使用手炉的场景。

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.
清代小说家曹雪芹的经典著作《红楼梦》其中一章描写了侍女为林黛玉送手炉的情节。

如今，在众多影视作品中，也时常闪现着手炉的身影。例如，《琅琊榜》《甄嬛传》里都有铜手炉出镜。

手炉通过烧炭取暖，可以说是一种小型移动式火盆，由炉身、炉底、炉盖（炉罩）、提梁（提柄）组成。为什么里面烧着炭，手炉却只是暖手而不烫手呢？

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
就暖而不烫了。