OUCH!!

So...yesterday I got the "ok" from my doc to go ahead and start exercising beyond simply walking. It's been 4 weeks since Alexis was born so he said I should be fine. So I convinced myself that running was what I was going to do for my daily hour "break" from my kids once Jared got home. I got my gear on and my friend and I set out. Ah, yeah, I soon found out how different it is to run in Utah than in Arizona...ALTITUDE DIFFERENCE ANYONE!!?!?!?!! My body was fine the entire time but my lungs, ouch! Well, we did successfully finish (not very fast but still good time) and I was proud of myself until this morning when I could barely roll out of bed. I had forgotten what it was to really exercise and the aftermath!! I have been sore all day. Maybe I was a little ambitious but I really enjoyed myself, well everything except for being sore all day today. So in light of my achiness I pose these questions to anyone willing to answer... Are there any tips or tricks for running in such high altitude? How about for running in a colder climate? I bundled up so much before leaving I was roasting halfway through my run! Let me know of anything because all advice will be well welcomed;)