At total rest, especially at high room temp, I feel air is not enough for me. Pulse oximeter justifies my feeling, it does show some lowering in oxygen saturation down to 93-94%. Funny thing is this feeling totally dissapears if I breath cold air from AC or start exercizing even with very aerobic exercize, then everyting comes to normal and better, and my lung function becomes pretty good, concidering just two years ago I quit (heavy) smoking. Spirometry shows no COPD, and CT shows very very light emphysema signs, not justifying my uncomfortable feeling at rest. Any idea what other possible dama- ges could cause my peculiar symptoms? Thanks a lot, Nik.