Bombardier beetle can spray boiling hot liquid that contains irritating chemicals, used as a defense mechanism against its enemies. The beetle stores two sets of chemicals separately in its glands. The chemicals are hydroquinone and hydrogen peroxide. When both chemicals reach the vestibule, they react and produce a near boiling point heat and a gas that drives the ejection. The spray can cause fatal damages to attacking insects.
Urry, Lisa A.. Campbell Biology (p. 43). Pearson Education. Kindle Edition.