The preferred clothing of the day, both inner and outer, was wool.  The creme de la creme was Filson, which shed water and retained its insulating ability even when wet, but was priced beyond the reach of the common man.  The rest of us wore fishnet underwear and blue jeans, with cotton flannel shirts.  If it got wet, we got cold.  We got cold a lot.

I did a lot of that backbacking with a British Korean-war surplus "Mancarrier" pack frame, which actually, I believe, was intended for people humping boxes of mortar shells. It had a waist belt of sorts, about one inch wide.  Strapped to the frame, I had an ordinary duffel bag, which if it got wet, leaked, and soaked my sleeping bag, and then I got cold.  Later, I used a plastic garbage can strapped to that frame, with my sleeping bag lashed on top, and if it got wet, I got cold.

Rain gear was most G.I. surplus ponchos.  Those worked, after a fashion, but were heavy.  There was no freeze-dried dehydrated food back then, so we carried rice and beans, and instant soups.

For treating water, we used Halizone tablets, when we bothered.

It helped, I suppose, that we were young, and doing the best we could with what we had.

This is now:

Now I can strap on a state-of-the-art internal frame pack, with padded waist belt, stabilizing straps which allow me to adjust the weight distribution between my shoulders and the waist belt, and a sternum strap which keeps everything together.  The pack is largely coated waterproof material, with outer pockets to keep my gear organized.  If it's not totally waterproof, it doesn't matter, because there's a rain cover which goes over the whole pack, and, besides, all the gear inside is in waterproof stuff sacks or zip-lock bags.

What isn't in waterproof sacks is clothing which doesn't absorb water anyway.  I'm wearing an inner layer of polypropylene underwear, nylon pants and shirt, and boots with Gore-tex "sock" liners to keep my feet dry.  My socks are another miracle synthetic fiber which wicks moisture away from the skin of my feet.  Outside that, if it's really cold, is polyester fleece, which feels like cotton, but absorbs so little moisture that it can be put on straight from the washing machine, and will dry from body heat in a few minutes.

The outer layer is Gore-tex pants and parka, or another miracle fabric, which sheds rain, but allow moisture to evaporate out.

The gist of all this is that I can stay warm, if not always completely dry, in the worst possible conditions short of total immersion in freezing water - for that one needs a "dry suit", which can be bought, too.

My sleeping bag is another synthetic, which retains most of its ability to insulate even if wet.

I can go into the woods, confidant that under any set of conditions I will encounter, I can stay warm and functional, i.e., I can avoid hypothermia.

We have lightweight stoves, and filters to purify our water.

For someone who likes to be outside, that is a gift nearly beyond price.  I am grateful almost beyond words for the gear which has brought me the outdoors, brought me the ability to head up the Harding Icefield Trail in Alaska, or the Berg Lake Trail in British Columbia, and know that I have gear which will allow me to be warm and comfortable no matter what the unpredictable weather does.

It isn't foolproof, of course, because fools are so ingeneous, and so numerous.  If you want to go mountaineering at extreme altitudes, you still better know what you are doing.  But thank goodness for it, for I am not a fool, and it allows me to wander about safely in the outdoors in conditions which, in my youth, would have caused my death.

I said to someone once that I'd have killed someone I really liked, when I was young, to get the gear I can buy today in any well-stocked outdoors store.  I was kidding, of course, but the gear we can buy today is wonderful.

If the existence of this kind of gear comes as a surprise to you, feel free to ask questions, and I'll steer you toward folks who can supply you.

Oh, yes.  Cotton clothing does kill above the timberline.  And below it too, in some places, like Canada and Alaska.  Cotton has its place - in hot dry climates, i.e., the desert.  Nowhere else.