I have made two trips across the Grand Canyon, rim to rim, both is June and wearing boots with Gore Tex. Were my feet hot, you bet! My whole dam body was hot. As other have so aptly noted, good socks are the key. (Thanks Shrap for the suggestion on Fits.) Hot or cold weather, If I am out all day, or on a pack trip, I like to change my socks part way thru the day. Sure feels nice to air out the feet and put on fresh socks. Never have suffered from a blister either.
