http://code7700.com/hypoxia.html - new link, added 8/21/2015
2009 Training notes: Symptoms of Hypoxia
Fuzziness or thick feeling in the head
A general slowness of thought including poor or lack of judgement
A poor or failing memory
Clumsiness
Unnatural feeling of well being (euphoria)
Mental fixation on unimportant tasks
Loss of visual sharpness
Dimming
Tunnel vision
Reduced colour vision
Occasional deep sighs
Blueness around lips and fingernails
Hyperventilation