頭腦發熱 [头脑发热]

Jyutping tau4 nou5 faat3 jit3
Pinyin tóu nǎo fā rè

Definitions (Wiktionary)
  1. verb, of head
    to be feverish
  2. verb, figuratively, idiomatic
    to act impetuously; to act out of a sudden impulse