Okay, you gotta keep this in mind: I’m always dressing up in that Dr. Forrester from MST3k costume, which is a jacket and tie and nice dress pants (usually), so in my head I just sort of assumed that this would be about the same, temperature-wise.  Remember, I don’t normally wear actual nice clothes much AT ALL.  Most of the time, it’s an act of maturity and class when I bother to put shoes on.  Thus, I had very little recent personal experience to draw from aside from that costume… where the shirt is short-sleeved and the jacket is honestly even thinner than your average t-shirt.  I was NOT prepared for how much warmer and heavier real grown up clothes are, and it kicked the CRAP out of me.  I mean, I know for a fact that plenty of folks were wearing way more uncomfortable stuff that day, and even I’ve worn far heavier stuff from time to time, but it’s different if you KNOW it’s coming and have time to mentally & emotionally prepare.  This was just, like, “SURPRISE, IDIOT, YOUR LIFE IS NOW A WORLD OF SWEAT.”