4:55 p.m. on September 10, 2009 (EDT)
If I understand correctly, you were wearing ONLY the base layer?
This type of clothing is meant to be worn as a system, in layers, thus the term BASE LAYER. You were only wearing one component of the layering system.
I don't think the layering system, or the ratings are way off, I think you do not yet understand how the layering system works.
The base layer is a 'wicking' layer, to pull your body moisture away from your body, it is not an insulating layer.
The next layer is the 'insulating' layer, which can be one or two layers in itself, I personally use one insulating layer for milder temps and carry an additional one for below freezing. I like micro fleece for the second insulating layer.
The other layers consist of a 'wind' layer, and a 'waterproof' layer.
You may, or may not, need both. Just depends on the conditions you will be encountering. Some people can use a 'shell' or 'rain suit' to do both, I think it depends largely, again, on the type of conditions you will be in.
For a wind beak I like a fleece layer with a wind stopping fabric, this works well for me in the areas I go to. If it starts raining / sleeting, I put on my Mountain Hardwear Shell. In dryer months I just carry a rain suit.
You simply carry adequate clothing that will meet any possible conditions you may encounter, (do you're homework of course) and adjust your layering system as needed throughout the day and as your activity level increases or decreases.
Some of this you can learn by reading, or from a mentor, and some you can only learn by getting out there and gaining some experience of your own. Everybody is different.
I have found out over the years that I prefer top layers that have quarter zips, as my body heat increases due to activity (backpacking) I can adjust my clothing just by unzipping a couple layers, allowing some body heat to escape. This cuts down on how often I must stop and remove a layer as the day warms up.
Here is an article you can read at the REI website:
http://www.rei.com/expertadvice/articles/dress+layers.html
I would also recommend you get a book or two that discusses these types of subjects.
Maybe try:
The Backpackers Handbook, by Chris Townsend and/ or The Complete Walker, by Fletcher Collins