saますmasu
1.

To lower the temperature of something hot by letting it sit or applying some cooling method until it reaches a more manageable thermal state for consumption or use.

2.

To diminish or calm heightened emotions or excitement, bringing feelings back to a more stable or neutral condition.

3.

To deal with someone in a detached or indifferent manner, suggesting a lack of warmth or affection in the interaction.

Example:

ちょっと冷まして、熱いうちは食べないように。