Nice, RnR. I thought about you in that heat. My friend the serial marathoner took a rare weekend off this week to rest up for the FIVE he's doing next weekend - I happened to run into him at the coffee shop Saturday morning and allowed as how it was a very good weekend to stay home.

My experience is I can't keep up with electrolyte loss even at more normal temperatures. Figure you lose 500-1000 mg sodium for every liter of sweat, and in those temperatures you'll probably sweat three liters an hour if not more. Plus the magnesium and calcium. Any more, I pre-load before an event, and after eight marathons I'm finally feeling like I've got a decent handle on nutrition and hydration to where I'm not in a complete mental fog by the finish, but even that probably wouldn't have been enough in 90°+.

I'm on the email list for Carmichael Training (never been a client of theirs, just got onto their mailing list somehow), and a couple of weeks ago they put up a blog post about nutrition and hydration in the heat. Maybe there's something in here you or your DH can use.