Hypoxia and why you should pay attention to your flight attendants....

Common Symptoms:

• Headaches
• Decreased Reaction Time
• Impaired Judgment
• Euphoria
• Visual Impariment
• Drowsiness
• Lightheaded or Dizzy Sensation
• Tingling in Fingers and Toes
• Numbness
• Blue Fingernails and Lips (Cyanosis)
• Limp Muscles

Hypoxia occurs when your body does not get enough oxygen. Symptoms vary from person to person. The percentage of oxygen in the atmosphere is constant but the partial pressure decreases proportionately as atmospheric pressure decreases. This translates to the higher you go, there are fewer oxygen molecules available at the pressure required for them to pass through the membranes in your respiratory system. Not enough oxygen eventually results in death.

At typical commercial airline cruising altitudes from 30,000-45,000ft above mean sea level, the time of useful consciousness available to don the overhead oxygen masks that drop down from the the cabin ceiling in the event of cabin depressurization is as follows:

30,000ft - 1 to 2 mins.
35,000ft - 30 to 60 sec.
40,000ft - 15 to 20 sec.
45,000ft - 9 to 15 sec.

This is why you are instructed to help yourselves first before helping others. You need to be conscious long enough to put th mask on. So next time you fly commercial, turn off the ebook reader, put down the sky mall, pay attention to your flight attendant's demonstration. You may only have less than a minute to survive. Oh and by the way if you smoke you'll have even less time.

Happy landings!