And I think this is key. Cotton is fine if you can keep it dry, but once you get it wet, it is miserable and potentially dangerous and difficult to get dried out again.

For example I can get sweaty while hiking and soak my base layer. With a wet Capilene silkweight layer, I can stop, take off my top layers, leave my base layer on, and after a break be comfortable and dry (assuming no rain, etc).

With a cotton tee, I'd still be wet and uncomfortable, and perhaps cold. Basically, I'd probably *need* a fire (or adequate sun, not often handy in this area) to get it dried out and it often can take a fair amount of time. Time best spent doing something else IMO.

I guess my feeling is that if I need to stay warm and I might get wet (in one way or another), I'd pick synthetics every time*.

On the other hand, I go to work in a cotton shirt, undershirt and pants.

But in my car, I have a set of synthetics in case I have to change modes.

YMMV.

-john


* Although, I'll admit, I only wear wool socks. But it keeps you warm while wet, and I try to keep a dry pair handy.