Tuga we did carry small canisters of O2 and used some as we hiked up above 12,000 feet. As we got close to the top it was basically take five or ten steps and stop to catch your breath. I arrived at the top about 20 minutes after my son. Not sure about the aspirin regemin as it may relate to altitude sickness. My son allways takes Ginko Biloba for a couple of weeks before going to Colorado or other high altitude hiking areas. He swears it helps but I have no proof one way or the other.