It is getting pretty hot or someone is playing with fire. The chat partner needs a cooling-down! The fire extinguisher serves as a precautionary measure to fight against a fire.
Learn more about the meaning
Emoji History
Development of the emoji in the Unicode lexicon
First included
The emoji โFire extinguisherโ was approved as part of Unicode 11.0 in 2018 and added to Emoji 11.0 .