thanks for the post.
Im not quite sure what happened. Usually pain from blockages in the exterminties would present as tightness or fatigue in the backs of the thighs or calves. What you describe sounds more nonspecific, especially since it went to your torso. If you were wearing tight clothes or leggings it might of been due to that, or chaffing from your apparel.
See if it continues, if so, discuss it with your physician.
Some people have allergic reactions to their own sweat. I know it sounds silly but it has been documented. It could be this.