熱氣換冷氣

Simplified: 热气换冷气

rèqìhuànlěngqì ㄖㄜˋ ㄑㄧˋ ㄏㄨㄢˋ ㄌㄥˇ ㄑㄧˋ

    • to meet enthusiasm with a cold, indifferent response

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
swapping hot air for cold air
Meaning
Being full of enthusiasm but getting a cold, indifferent response in return.

Sources