Many adults have childhood memories as vdychovali light gas helium , for example, to birthday parties and listen to their own unrecognized pitched voice that sounded like Alvin and the Chipmunks and The Wizard of Oz Munchkins . While it is generally harmless fun and inhale helium , it is not as safe as most people think . Breathing pure helium can be risky because it displaces oxygen demand . ( That is, when a person inhales helium , is not mixed with oxygen , so one can not accept or oxygen . ) In other words, the authorities need oxygen , but instead accept a pure helium , so the result is suffocation . One breath of pure helium can cause hypoxia ( lack of oxygen in body tissues for frothing ) and may cause dizziness . Another real breath of air ( oxygenated ) lets everything go back to normal. . If someone is going to inhale helium in this way , it would be wiser to inhale helium sitting down , because if a person gets dizzy is little likelihood that it could hurt helium .

článok pripravil Tibor Javorský