referring to a person's life or vitality as being extremely weak and hanging by a thread, often due to old age or severe illness

那位病重的老人已是风中之烛，气息十分微弱。

literally a candle in the wind; used metaphorically to describe a situation or entity that is extremely unstable and likely to be destroyed at any moment

在这个动荡的时代，小企业的生存状况如同风中之烛。