Don't argue with that hothead, he loses his temper over nothing.

hothead 是由形容词 hot（热的、激烈的）和名词 head（头）组成的复合词，字面意思是"热脑袋"，用来比喻"容易激动、脾气暴躁的人"，即"急性子"或"火爆脾气的人"。