If your brain isn't cool.

Then you are not either. Brains are a very predictable organ. When they are cool they work very well. When they are not cool they don't. This is why. Your brain represents about seven per cent of your body weight. Your brain, however, uses about seventeen per cent of the oxygen that you breathe in. That is a lot. The reason is that our brains require a lot of oxygen to stay cool. The oxygen is supplied to our brain by our blood circulation. This is accomplished by our big blood pump, the heart. As you can tell the brain is a very jealous organ. It demands a lot of the heart and lungs. This is, as I've said, because it needs to run at an optimum temperature. That temperature is approximately 98.6 degrees Fahrenheit. A steady flow of oxygenated blood effectively keeps our brains cool. The best way to keep our brains cool is to breathe. Deeply and regularly. We don't think about breathing much because it is an automatic process. Still it is wise to pause occasionally, especially while studying, and breathe deeply. Keeps your brain cool. And when your brain is cool it works.