If you get a career in any medical field then it's important to know about the functions of the body systems. Knowing about how they work will prepare you for what you need to know when you get that job. Learning these things in school helps prevent you from struggling with your career.
For some reason I have a little bit of doubt that this is related to your schoolwork, however this is important to learn to not do so by mistake. This would take a few minutes of inhaling fumes and is a very painful way to die. Even if it doesn't kill you, exposure can lead to brain damage and chemical burns. 5-10 minutes of non ventilated inhaling.
Tolerance can in fact cause an overdose, because the greater tolerance you can get the more of a certain substance your body will need eventually leading your body to take more than it can handle leading to overdose and death.
