i have a cotton tam and i live in Florida. as you should know, Florida is hot as balls everyday, all day. i thought cotton was supposed to breath really good, but its hot as crap. so are other materials such as hemp, wool, or w/e else there is, that breath any better? i mow grass a lot, so i wear it then to keep dirt, grass, and other crap from flying into my hair. but its so hot that i start sweating profusely and my head gets really nasty sweaty smelling from being bundled up in the tam.
yeah, maybe tie a t-shirt or something on. maybe combine that with a dunk in some fresh water beforehand. it should dry by the time you're done working. i think it has more to do with all that hair being held so closely to your dome. when they're down and loose, my head breathes a lot better.
actualy i find tyimng or tucking mine into a wool tam is far cooler then down just to get em up off my neck..then i dump water over my head alot a looser knot helpes em breath i wish i had a hemp 1 oh and i do often just tie em up ontop alot the hat 1 want ios like 1 of those cone shaped african hats bit with the point in the middle cut odff so i can thread the dreads thriugh the hole and theyd hang off my back n shulders and ifd get some shadetoo