I am bored at work (slow day) so researching various bits on wikipedia. I moved onto tanks and found this regarding the Challenger 2....
Like every British tank since the Centurion, and most other British AFVs, Challenger 2 contains a boiling vessel (BV) 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.[7] This BV requirement is general for armoured vehicles of the British Armed Forces, and is almost unique to the armed forces of the UK.
I love it, we equip all our armoured fighting vehicles with a kettle to produce tea, how very civilised...right chaps, time to bring democracy to those barbirans!