This is probably more for travelling and camping this summer than Brexit related nonsense but still:
- can you put them on a grass surface?
- how long do they take to cool down? could you boil water and store it back in the car boot soon after or would you be waiting hours?
- can you cook food on them without water in the kettle?
- can you use them on top of any traditional gas stove?
(I'm guessing no; it depends; yes and of course, but I've been daftly wrong before on these things!)