noun
summer fires and winter fans; useless things
A yojijukugo describing something that is out of season and therefore useless, like a heater in summer or a fan in winter. Often used metaphorically for things that are untimely or of no practical value.
彼の提案は夏炉冬扇のようなものだ。
His proposal is like a summer fire or a winter fan—completely useless.
Both mean something useless, but 夏炉冬扇 specifically emphasizes being out of season or untimely, while 無用の長物 is a more general term for a useless object or person.
A yojijukugo composed of 夏 (summer), 炉 (hearth/fire), 冬 (winter), and 扇 (fan). The phrase originates from classical Chinese literature, illustrating the idea that something is only useful in its proper season.