Please remember that while helium is non-toxic, it is not oxygen. We need oxygen to survive. Breathing in too much helium will start to limit the amount of oxygen going to your brain and other parts of your body, potentially resulting in you passing out from oxygen deprivation. Also, NEVER breath helium straight out of a tank. The gas in that case is under great pressure and can cause a pneumothorax, which is a VERY serious condition.