Nice! It looks like you guys (ladies, haha) had fun! I wish I had access to neat trails like that.
About the coat thing (at least I've found this to be true about my part of Oregon) is that once it gets down below freezing, somehow it doesn't feel cold anymore. I've been out in dry 15*F weather just in jeans, a sweatshirt, and converse and not been cold.
Alternatively, maybe it's because Heather and I are both redheads - the fire in our bellies keeps us warm.