This emoji is often used metaphorically to mean resolving a crisis or shutting down a controversy. For instance, if a big fight breaks out online, it can be used to mean, "Everyone, calm down!"

It symbolizes the role of a "savior" who resolves not just actual fires, but also last-minute project crises or conflicts between friends. It's useful for wittily presenting yourself as a problem-solver, like saying, "The fire extinguisher has arrived to put out this debate!"