Run in 'sunny' Florida

Yesterday was a rest day, I travelled to Orlando to attend a manufacturing conference. This morning (Sunday) I got up to run @ 5 AM hoping to take in some warm FL weather. Right!! 45 degrees and I have a t-shirt and shorts and am running with my head light. I freaking froze. I only got 42 minutes in (heck of a negative split to get warm). Even so my average HR was only 149. No idea on mileage.