Well, British Tanks have a tea brewing device [1]:
"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."
(An acquitance of mine has a kettle like yours at 1000m elevation, and with the thermostat set to 100°C it does not stop boiling of its own accord).