A young man, Tad, challenges Ash to a Pokémon battle, having heard about his reputation. He uses an extremely talented Poliwrath, which beats Pikachu. Ash decides to use Charizard, which is a mistake, as it is not trained and is ice beamed solid. Tad says he will rechallenge when Ash has trained it properly. Ash is panicked and struggles to get his Charizard out. Once it is, its tail flame is almost dead, and Charizard is very cold.
All through that night, Ash, Misty, Pikachu and Tracey rub Charizard with blankets, Ash rubbing his hands almost raw. But while Misty, Pikachu and Tracey take turns, and also do other things like get firewood and rest, Ash is there all night. He tells Charizard he knows he isn't a good trainer, and may make a lot of stupid mistakes, but he just wants Charizard to get well, and some day be good enough for it to respect him. Charizard remembers its past as Charmander.
The next day, Team Rocket steal Pikachu, and Charizard flies off with Ash on his back to rescue them. Charizard actually follows Ash's recommendations to get Pikachu back. Tad, hearing the disturbance, has come to see what's going on, and realises that Charizard is now obedient. They fight again, and Ash wins. He has earnt Charizard's respect after so long.