There was an article in the Charlotte Observer about that this morning. I was gonna post it, but ya beat me to it...
My neighbor had a 3 year old black lab that died last year in 90 degree heat after he walked him on a leash to the newspaper box (about 1/2 mile)[:@]
If anyone wants a comparison, put on a fur coat and go sit in the yard for a few minutes...If that doesn't work, get out in the sun and run around a bit[&:]