Loose the cotton. You need extreme moisture wicking garments. Silk may work well. As far as preparing them, be smart about it. Don't clean clothes and then contaminate them getting them out. Think about it and act accordingly. Personally I pack each piece of clothes in it's own zip-lok bag. I can rifle through the stuff as often as I care to finding what I want for the day without ever touching the stuff and it really isn't expensive or trouble.

Warm wether's tough to hunt in. Work on not impacting the area you hunt in. Don't shuffle your feet, don't touch anything, don't rub up agaisnt things, walk softly, critters feel sound with their feet/paws. Move slowly and deliberatly. You maybe giving away your there even before they smell or see you. Don't hunt down wind or in swirling winds. Change your clothes a couple hundred yards away from your site, Sit down there and cool off if you need to. Don't move around or make noise when your hunting.

After all this work make the shot count.