According to Tolkien there were only two things hot enough to melt the one ring: the fires of mount Doom or a dragons breath.
A real dragon has no limit to their fire breath. So long as they can breathe, they can breathe fire.
Most dragons do breathe fire, but only aquatic dragons do not Not necessarily. Some dragons might be capable of spitting venom or injecting venom, and some may breathe poisonous gas, but not all non-aquatic dragons can breathe fire. Also, some amphibious dragons can breathe fire.
No.
In "The Smallest Dragonboy" story, dragonriders give their dragons a special drink made from lime juice, salt, and crushed hot peppers to help them breathe fire. The drink is known as "firestone."
They breathe through there tongue!!
You can breathe in either. Given a normal environment both hot and cold water will evaporate and become water vapour (change from a liquid to a gas). All else being equal the hot water will evaporate faster, but the cold water will still evaporate. For example, when you sweat, your sweat is not particularly hot, but it is the evaporation of the sweat that cools you down. You can therefore breathe in the water vapour from either hot or cold water. Just for absolute clarification - the above assumes the questioner is not asking if you can breathe under water; which clearly you can't unless there is something a little fishy about your character! :-)
no it doesn't
No, they breathe fire through their mouth.
Not recorded
yes
Dragons can't eat hot wings
Dragons fly. Tigers do not. Dragons breathe fire. Tigers do not. Dragon vs. Tiger = Crispy tiger
no,hot water does