Well, a lot of posturing back and forth in this thread...

I invite any of you to come to Phoenix this time of year and tell me, truthfully, that adding a base layer makes you cooler. Oh yeah, we're rockin' about 112 ~ 115 degrees Fahrenheit this week. That'll put the temperature above 120 coming off the pavement. There ain't no way I'm wearing extra in this heat.

Personally, I think its just a fad.

But if you say it works for you, then who am I to argue? We can certainly agree to disagree!