I dunno, I don't think it's abnormal. When the weather is cooler, I'm cold after riding. You vasodilate during exercise to pump more blood to your muscles (and cool them off), but you lose a lot of heat too by this process. I imagine it as if you were drinking alcohol - you feel warm (during) but you're actually getting cooler because your vessels are so open. I would then think to guess that the body is just taking a while to normalize after intense exercise and heat loss, and for some of us this just takes longer. I normally feel cold so it doesn't bother me. Haven't died yet either