Hey now, the Midwest gets real hot in the summer. Remember what happened to Korey Stringer, the offensive tackle for the Vikings, a few years ago in that Minnesota summer heat.
When I played soccer, I found it easier to score at the end of games played in high temperatures. It just seems like EVERYONE is tired and players get sloppy. Sloppiness by the defense usually hurts a lot more than the same from the offensive players.
I hated games played in the freezing weather. Trying to get a good strike on a ball that's frozen when you can no longer feel any of your extremities makes things real difficult.
I concur with everything you said.
Having grown up in Peoria, IL, I'm well aware of midwest heat waves, but I suspect they hadn't anticipated upper 90's when they scheduled the exhibition in Blaine, MN! (I didn't realize the heat wave was nationwide until I saw the paper today - 115 in Pierrre, SD, yesterday!)
I agree that extreme heat favors the offense. First goal I ever scored in a competitive game (as a rookie at age 46 - that's how late I came to soccer!) was in extreme heat. I curved a ball right into the upper left corner of the goal (idiot that I am, I admitted to people that it was intended as a pass! Fortunately, I scored an INTENDED goal later that same game.).
I've always figured that the ideal temperature for players is about 10 degrees cooler than the ideal for spectators: early spring or late fall, about 55 degrees; May thru October, about 65 degrees. (Of course, good luck on getting in a game at 65 degrees in July or August!) Although extreme heat may be more dangerous, if I had to choose I'd take it over 34 degrees and windy (including games played in snow and/or sleet).