lose your cool
US /luːz jʊər kuːl/
UK /luːz jʊər kuːl/

1.
perdere la calma, arrabbiarsi
to suddenly become angry or upset
:
•
He tends to lose his cool when things don't go his way.
Tende a perdere la calma quando le cose non vanno come vuole lui.
•
Even under pressure, she rarely loses her cool.
Anche sotto pressione, raramente perde la calma.