my day hikes range from 10 - 25 miles round trip. summer temps are 85 - 105, mostly w/o cover. i carry a 15 - 18 lb pack. mostly water. i do not perspire, i sweat.

when i would stop for lunch i got tired of feeling like i was a soaking wet dishrag while wearing cotton. sure, it dried, but i had to take it off to get it to do so.

the synthetics i use dry quickly while wearing them, do not rub me the wrong way, protect me against nature - bugs, thorns, abrasions - and have lasted a lot longer than the cotton i started out with. and mine don't get an odor.

i'm sure there's a great place for cotton - but for me, in my circumstances - been there, done that, no bueno.

just my $.02.