That proves it! Too much fresh air can be harmful. Wizard, when that happens you should pull out a platic bag, put it to your mouth and nose and breathe in and out steadily till your bearings come back to you. After that, when you return to so called "civilization" go downtown for a good breath of smog and that should hold you till the next time you are exposed to fresh air.
On a more serious note, how far down streem from the springs did you find the dry section of the creek? Did you notice any mosquito larvae in any stagnant pools?
Thanks very much for sharing your day and making us all envious.