My first case was during a 100k attempt. I knew it was going to be hot, but not even the weather people predicted this kind of heat. I left the start before 7am..by the time I started on Edgewood (short moderate climb) at 830am, it was over 90. I was already throwing up by that point, but knew that there was a rest stop not that far up ahead and some light rollers between me and it, and I thought that if I could get to it, I could rest a while and recover. I got to about 5 miles short of the stop, 25 miles into the ride, and I had to stop, as it was near 100 at that point at 10am in the goddamn morning. Fortunately, at that point there was a Team In Training event going on at the location I stopped at, and as I huddled on a bench, shivering and not sweating, the two ladies manning the water cooler noticed my distress, and tried to start cooling me down, as I was just basically overheating despite being full of water and cytomax. One of them had a son who was a paramedic and she called him to ask what to do, and followed his instructions, which definitely helped. They also called the SAG for the ride I was on, and arranged for my pick up. They continued to attend to me until the SAG showed up, and once I got back to the start, the folks manning the tables there (it was at a jewish school) tossed me into an air conditioned room, fed me what must have been an entire watermelon and a gallon of gatorade over the next two hours. All the folks helping me had been to Israel in the dead of summer and had experience with this, so they knew how to get me cooled down. Once they deemed me ok, I called the bf to bring me home, and I slept the rest of the day away. Took me 2 days to recover from that. I tried another warm ride later on in the summer, and had the same thing happen (was 92 out so wasn't quite as hot and the route was shaded), so I know now that my body will simply not tolerate anything over 90.

I wish it was just a matter of conditioning, but it seems to be a hard limit that my body simpy will not allow me to exceed.