Heat + Humidity = Wall

[BlessedB]

Ladies, y'all are the best!
Thank you for your thoughtful ideas - you've given me much to ponder and much to do.
I take two of those big Camelbak bottles of water with me - I thought they were a liter each, but it looks like only 750ml or 25oz each. I was able to fill up once while out, so drank a total of three, plus the iced coffee of course. I will switch at least one to a sports drink, as much as I don't care for the taste. I'll take more snacks as well, and work on my shorter rides. Great idea on getting my head wet - I do this while mowing the lawn. I guess what really threw me was that this was not my first time this summer doing a 40-mile loop - in fact, I'd done it weekly, about 4-5 times, without hitting a wall. Thank y'all again - I so appreciate your generosity of spirit and wisdom!