godan verb (-su), transitive verb
cool down; let cool
Transitive: actively cooling something hot down to room temperature or a comfortable warmth, not necessarily cold. Common with food, drinks, and heated objects.
熱いスープを少し冷ましてから飲んだ。
I let the hot soup cool a bit before drinking it.
お風呂のお湯が熱すぎ
The bathwater was too hot, so I added cold water to cool it down.
godan verb (-su), transitive verb
dampen; spoil; throw a damper on
Figurative use: cooling down excitement, enthusiasm, or a good mood. Often used with nouns like 熱意, ムード, or 盛り上がり.
彼の一言が場の雰囲気を冷ました。
His one remark dampened the atmosphere.
悪いニュースが祝賀ムードを冷ました。
The bad news spoiled the celebratory mood.