After one use: inside a shelter, stove protected from the wind, around -8°C, something like that. Two tablets were not able to boil 300 ml of water in a cup with a lid. For summer: okay, there’s a chance it could work, and combined with a metal plate as a fire base it makes the lightest possible set. However, performance in conditions other than ideal is pretty much laughable. I barely managed to hydrate my freeze-dried meal with lukewarm water, but what choice did I have?