OK event at Clinton Overlook. Eric S set the course. The course was nice with no rough vegetation.
I was at the start helping people get going and had decided I'd skip running the course. But Eric talked me into it. So I ran, without any warm up and not pushing. Despite not pushing, my h.r. was high. Some of that's the heat and humidity. It was ok in the shade, but the sun was warm. Lots of sweat.
I stepped on a thorn near control 7. The thorn went through the bottom of my shoe. I tried to pull it out quickly, but it broke off, leaving the thorn in the sole and my foot. I walked carefully to the trail/sidewalk, sat down and was able to pull it out.