In ancient China, without electricity, how did people stay cosy at home during freezing winters? The answer lies in warming baskets, which have been used for more than 2,000 years. A traditional warming basket featured a charcoal brazier beneath a bamboo cover. One of the earliest written references to the device dates back to the Qin and Han dynasties (221 BC–220). At first, the basket served as a stove to keep a room warm. Later, people added incense to the brazier and placed a basin of water...