I learned my lesson after this week's MW, when the half was below 50 until the sun rose. Being from MN I got a bit overconfident and thought I'd be fine in short sleeves and shorts, of course the FL humidity is a different kind of cold and I forgot how long it takes the sun to rise when you start at 5AM. I also forgot that I don't run the WDW races as fast as I usually race and thus I don't get as warm as I usually do. I about froze my arms/hands off (legs/torso/ears were fine, funny enough).
I actually started with hand warmers which is the funny part, and tossed them after a few miles because my hands were plenty warm. Turn out they were warm BECAUSE fo the hand warmers, and tossing them was a really dumb decision