Originally Posted by Dean V

I can't see how this is even a discussion.
Forget the science. You don't need it.
Go for a ride on a hot day with a base layer on. Remove it mid ride and see if it is cooler.
I have always found it to be cooler without it.
Has anyone found otherwise? I am not talking about theory, but personal experience.
Anyone ever seen a Pro racing on a hot day wearing a base layer?