‘热血’ literally means 'hot blood' — combining 热 (rè, 'hot') and 血 (xuè, 'blood') — and metaphorically conveys intense passion, fiery enthusiasm, or unwavering idealism. Unlike its literal physiological meaning, this compound is almost always used figuratively to describe a person’s spirited, courageous, or deeply committed attitude, especially in pursuit of justice, dreams, or collective causes.

It often appears in contexts involving youth, activism, patriotism, sports, or creative endeavors — for example, describing a young volunteer’s dedication or an athlete’s fierce determination. While it carries positive connotations of vitality and moral courage, it can occasionally imply impulsiveness if used critically (e.g., ‘too much热血 without strategy’). The term is common in written and spoken Mandarin, particularly in inspirational, literary, or media discourse, and frequently modifies nouns like 青年 (youth), 男儿 (man), or 精神 (spirit).