lose one's cool
To get excited, angry, or flustered.
Выйти из себя, потерять терпение.
The teacher lost her cool because the students misbehaved at her lesson.
Учитель вышел из себя, потому что студенты плохо вели себя на уроке.
Despite the boos from some in the audience, the actors on stage never lost their cool.
Although the group of skiers were in danger from an apparent avalanche, their ski guide never lost his cool.