"Similar to every British tank since the Centurion, and most other British AFVs, Challenger 2 contains a boiling vessel (BV)[citation needed] also known as a kettle or bivvie for water which can be used to brew tea, produce other hot beverages and heat boil-in-the-bag meals contained in ration packs.[9] This BV requirement is general for armoured vehicles of the British Armed Forces, and is unique to the armed forces of the UK."

[1] http://en.wikipedia.org/wiki/Challenger_2#Crew_and_accommoda...