4 Mile Run Today

It said it was a trail so I guess it counts. This is a rails to trails project that is underway. This is part of the trail which is going to connect southern Ohio with Northern Ohio some decade. This trail has been improved since the last time I was on it, less cinders, maybe they all washed away since last summer.
It was a bit hot out today at 330pm, since I left work early. It was about 90 with 100% humidity. When I started running, you weren't breathing air in, I seemed to be eating air, it was so hot and heavy. But hey, I was running!!
And for me, running a bit fast! I actually charged the Garmin so I glanced down and noticed I was running a 9.50 pace-WTF was up with that???? Maybe no run for a week and total flat running space despite the heat?? In fact, I kept around a 10-ish minute mile pace for about two miles. Then I drank some water and immediately broke out into chills. Maybe running at 4pm with no hat and running a bit fast really wasn't the best idea. How on earth did I get so overheated in just two miles? And why didn't I care more? I was having this strange little fight going on. Mentally and emotionally I was so into the run, and then I had Body on the side saying "hello, I really shouldn't be cold now! Did you even notice my chills? Is this heat stroke or heat exhaustion, but does it matter and why isn't anyone paying attention to me?"
I slowed down on the two miles back, stopping to walk when the chills got a little stronger-after all, what could I do? I'm out in the middle of kind of cornfields, behind people's houses. I actually was still in a very good mood although Body was still pretty miffed. It was about a 1/4 mile walk back to my car, so I guess I must have been hot, since the air felt pretty good for the walk back. I'm still convinced I had a good run there, it felt so good to get out and run!