冷めないうちに

before it gets cold

→ 冷める
phrase Rare #34,875
before it gets cold Used when telling someone to eat or drink something while it is still warm or hot. うちに means “before” or “while the current condition lasts.”
JA: 冷めないうちに、ピザを食べてね。
EN: Eat the pizza before it gets cold.

ここに置いておくから冷めないうちに飲みなさい

I’ll leave it here, so drink it before it gets cold.

— ハウルの動く城 (2004)

冷めないうちに召し上がれ

Please enjoy it while it’s still warm.

さあ冷めないうちに食べな

Come on, eat it before it gets cold.

— 魔女の宅急便 (1989)

スープが冷めないうちに飲んで

Drink the soup before it gets cold.

食事冷めないうちに食べましょう

Let's eat before the food gets cold.