Proverbs 19:19: A hot-tempered man must pay the penalty; if you rescue him, you will have to do it again (NIV).
A hot-tempered child often gets into trouble. If a parent rescues him from the consequences, he may take advantage of that kindness and the lesson will have to be repeated. How many times have you rescued your child from the consequences of irresponsibility—taking forgotten homework to school, making excuses for them when they are late, or replacing something they carelessly lost—only to have the same behavior repeated?
We are called to train our children, but the best way to learn real responsibility is to give them a chance to succeed or fail on their own. One of the hardest things to do is to give our kids consequences for poor decisions. It is tough for us to see them "pay the penalty" and sometimes, we feel their mistakes reflect poorly on us. But just like the person who rescues a hot-tempered man, our parental rescues only postpone the development of responsibility.
Have clear boundaries and expectations for your kids, but allow them to experience the consequences of their decisions.