I was in a minor car accident when I was younger, and because I'd hit my head the paramedics insisted on taking me to the hospital to get checked out. It was the only time I've ever been in an ambulance, and one of the things that stands out in my memory is the EMT putting the oxygen on my face and apparently trying to lighten the mood by smiling and saying "breathing this pure oxygen is totally going to give you a natural high."

Well it didn't give me a natural high, and according to this new research it may have actually done some damage instead. Testing shows that inhaling pure oxygen has exactly the opposite effect than intended: it triggers the release of hormones and chemicals that can potentially hurt the brain and heart, and that interfere with normal blood flow and oxygenation of vital organs. It seems a mix of carbon dioxide and oxygen proves to be much better, or even just plain old room air -- which they already use for patients in Europe. Who knew?