cool (someone/something) down/off
phrasal verb with cool verb uk/kuːl/ us/kuːl/
B2 （使）冷却下来，（使）降温;（使）凉快下来
to become less hot, or to make someone or something become less hot
She waited until her coffee had cooled down before taking a sip. 她一直等到咖啡凉下来才抿了一小口。
We went for a swim to cool off. 我们去游泳好凉快一下。