I’m not sure if it was purely down to the heat, just that it tipped things over the edge for me. I think there were also a couple of underlying problems, one long term, one short.
Warning! Bodily functions discussed ahead 😐
The long term problem is possibly long term fatigue, the last couple of years I’ve done six or seven ITTs per year and it’s probably caught up with me. Since about October last year I’ve struggled to get the enthusiasm to do training of any kind or even commute on the bike – I’ve probably averaged less than a day a week.
The short term problem was that I think I ate something at breakfast that didn’t agree with me. I started feeling queasy about three to four hours after breakfast which is about the usual timescale for this to appear (I vaguely remember 3-6hrs being one thing, 6-12hrs being another cause, 12-24hrs a third class). My stomach was in knots and I was mostly retching and dry vomiting. The last bout of vomiting brought up the last of the breakfast and I was fine after that and could take fluid and foods on board but by then I’d made my decision to quit.
I know what you mean about the body maintaining its balance. I was only drinking plain water, I’ve not used electrolytes for some years now. There were very few salt stains on my clothing, I was sweating steadily but not profusely.
Losing fluid through sickness is only going one way really especially in hot weather and I’ve no regrets about scratching when I did. I knew I could get myself out, even though it might take some time and might be a bit painful due to cramp and blisters. Pride might take a knock but then, it’s only pride.