A little dizzy

I think I jumped back into running too quickly here in Sija. I didn't realize that two weeks of running at sea level while at home would make me have to reacclimate to the altitude in Sija -- 9,000 feet mind you. Monday was okay (6 1/2 hilly miles); Tuesday was hard (5 hilly miles); today was dangerous. At the beginning I felt better, but at about 20 minutes the hills were killing me (it's impossible to avoid hills here, by the way). We ran about 6 miles and when we finished I felt dizzy and light-headed. I was definitely on the verge of fainting! But I made it home in time and managed to hydrate, eat and rest. Now I feel fine, but maybe I'll take tomorrow off?