熱気

The word refers to both a physical sensation of hot air and a metaphorical atmosphere of intense excitement. When used physically, it describes the palpable heat filling a room or an area, often implying a sense of heaviness or intensity (e.g., in a kitchen or a sauna).

In a metaphorical sense, it describes the collective energy, passion, or fervor of a crowd. It is not about an individual's internal feeling, but rather the "vibe" or "electric atmosphere" of a place where many people are excited about something.

It is important to distinguish "熱気" (nekki) from "熱意" (netsui). While "熱意" refers to an individual's strong will, passion, or eagerness to achieve a goal, "熱気" refers to the external, shared atmosphere of excitement. You have "熱意" (passion) for a project, but a stadium has "熱気" (excitement/fervor).