Tom's mother told him, "Do not go outside without your warm coat, Tom. It is very cold and there is a lot of snow on the ground. I f you go without your coat, you will catch cold, and you will be sick."
"But I feel quite warm," said Tom.
"Yes, you do now," said his mother. "That's because there is a big fire in here. Outside there is no fire, and the cold wind blows. If you have no warm coat on, you will feel cold."
However, Tom thought he knew best, so he went outside with no coat, and he caught a bad cold and cough. He was very sick and had to stay in bed.
Tom was supposed to play on the frozen pond with his friends Jack and Will the next day, but now Tom was too sick to go. When he was in bed, Tom thought about how silly he had been. He would try to do all he was told when he got well again.
frozen: when water turns to ice, it is "frozen";
well: feeling good, not sick.