“头盔”的英语表达是 helmet ，读音：英 [ˈhelmɪt]；美 [ˈhelmɪt] 。
例如：
You must wear a helmet when riding a motorcycle.（骑摩托车时必须戴头盔。）
The firefighter put on his helmet before entering the burning building.（消防员在进入着火的大楼前戴上了头盔。）