-Wear light colored (white preferably) clothing, light weight, and loose fitting clothing/hat. This will minimize solar radiation absorption and maximize cooling from sweat evaporation.
-Don't wipe off sweat... let it evaporate.
-Walk at a slow pace and walk more hours to minimize metabolic heat.
-Walk mostly in the early morning and evening hours... take a shade based siesta during the heat of the day. If natural shade is not available, use a white Tyvek or Space Blanket tarp.
-If possible, sleep in a hammock to maximize convection cooling of your bottom body.