The Gemara here discusses the concept of קים ליה בדרבה מיניה which is the following principle: If someone does a prohibited action that entails both a mortally severe punishment (such as heavenly death decree) and a financial penalty, he is exempted from the financial penalty. For example, someone commits an act of theft while simultaneously taking the object from a private domain to a public domain, since he is mortally liable for violating the Sabbath, we exempt him from the additional financial penalty. There is something similar but not identical under in secular law known as the Multiple Punishment Doctrine.

What we can learn from this principle is an approach of compassion and decency. When punishing children, it is also important to consider this idea. Often a teacher or parent, floundering for authority, will heap one punishment on top of another. The truth is, we cannot compel a healthy human being to do anything he or she does not want to do, including children. Punishments, as well as rewards, are similar to guard rails on the highway. The primary purpose of a guard rail is not to stop a car from driving off the road. That is, it only fulfills its function in the worst case scenario. The true purpose of a guard rail is to remind the driver that there is a boundary on each side, and to help him orient himself far from the edge of the road so he never hits the guard rail in the first place. Likewise, rewards or punishments at best serve as reminders of valued ideas, but they are,  in and of themselves, poor incentives. They are about as helpful as highway guard rails. Guard rails do not make safe drivers, that is, the drivers that bang into them are not considered safe, rather drivers who respect them. So if you find yourself throwing on one punishment after another, the chances are there is a different problem and no punishment is really going to help.